| |
Taxotere®
and Genasense(TM) Active in Refractory Prostate Cancer-(ET-17/09/2003)
According
to results recently presented at the 39th annual meeting of the American
Society of Clinical Oncology, the treatment combination of Taxotere® and
Genasense(TM) appears to produce anti-cancer activity in hormone-refractory
prostate cancer. The prostate is a walnut-sized male sex gland that is
located between the bladder and rectum. The prostate is responsible for
secreting a substance that forms a component of semen. Treatment options
are varied for patients with prostate cancer, often depending upon the
stage, or extent, of the disease. Metastatic prostate cancer refers to
cancer that has spread outside the prostate to distant sites in the body,
often invading vital organs and bones. One component of therapy for prostate
cancer is called hormone therapy, in which levels of male hormones, which
have growth stimulatory effects on prostate cancer cells, are reduced
in the body. However, prostate cancer that ultimately stops responding
to hormone therapy is referred to as hormone refractory prostate cancer.Researchers
are evaluating novel therapeutic approaches for patients with this disease.
Response to treatment
is often measured by prostate specific antigen (PSA) levels in the blood.
Prostate specific antigens are small molecules normally shed from prostate
cells into the blood and when elevated, often indicate growth of prostate
cancer. An obstacle to achieving optimal therapeutic outcomes in patients
with cancer is that cancer cells become resistant to therapy. Genasense
(oblimersen sodium), a biologic agent still in clinical trials, targets
a protein called Bcl2 that is thought to play an important part in the
development of treatment resistance in cancer cells. Bcl2 is a protein
that exists in delicate balance with other related proteins and its function
is to prevent cells from apoptosis (death). Through several mechanisms
not entirely understood, Bcl2 proteins protect cancer cells from the lethal
effects of chemotherapy. Various types of cancer, including prostate cancer,
are associated with high levels of Bcl2 proteins.
Researchers from
the Cancer Treatment and Research Center in San Antonio TX, and the British
Columbia Cancer Center conducted a clinical trial evaluating the combination
of Taxotere and Genasense in the treatment of hormone-refractory prostate
cancer. Taxotere (docetaxel) is a chemotherapy agent that continues to
demonstrate promising activity in the treatment of prostate cancer This
trial included 29 patients who had received extensive prior treatment,
including hormone therapy, chemotherapy and/or radiation therapy. Following
treatment, nearly half (48%) of all patients had at least a 50% reduction
in their PSA levels. Of the patients who had cancer that was visible on
x-ray or could be measured on physical examination, 31% experienced an
anti-cancer response of these areas. Treatment was well tolerated.
The researchers concluded
that the combination of Taxotere and Genasense provides anti-cancer activity
in patients with prostate cancer that has stopped responding to standard
therapies. These results have prompted the initiation of a trial directly
comparing Taxotere alone to Taxotere plus Genasense in order to formally
assess the true clinical benefit of this treatment combination in men
with hormone-refractory prostate cancer. Patients with hormone-refractory
prostate cancer may wish to speak with their physician about the risks
and benefits of participating in a clinical trial further evaluating the
addition of Genasense to Taxotere or other promising therapeutic approaches.
[Top]
Prostate
Cancer Risk Highest with Affected Brother-(Reuters Health-15/09/2003)
To have a lower risk
of prostate cancer, it's better to have a father with the disease than
a brother, new research suggests. Of course, having no family members
with the disease carries the lowest risk. This finding is the opposite
of what is seen with breast cancer, in which a person's risk is lower
if they have a sister with the disease rather than a mother, lead author
Dr. Deborah Watkins Bruner said in a statement. "This may suggest that
the risk may be related to shared environmental factors such as dietary
exposures or age of onset of disease, which might reveal a stronger genetic
risk," Dr. Bruner, from the Fox Chase Cancer Center in Philadelphia, added.
The new findings
are based on a review of 24 studies that looked at a person's risk of
prostate cancer when different family members were affected. The report
is published in the International Journal of Cancer. Compared with having
no family members with prostate cancer, having any relative with the disease
raised the risk by 93 percent. If any first-degree relative such as a
father or brother was involved, a 120 percent increase in risk was seen,
whereas disease in a second-degree relative, such as an uncle, raised
the risk by 88 percent. Having a father with prostate cancer doubled a
person's risk of the disease, while having an affected brother nearly
tripled their risk. These findings could be used to better gauge prostate
cancer risk and could potentially reduce unnecessary screening tests and
diagnostic surgeries, Bruner noted.
[Top]
Test
Predicts Death After Prostate Cancer Therapy-(Reuters Health-16/09/2003)
After treatment for
prostate cancer, the amount of time it takes for a certain blood marker
to double predicts a person's risk of dying, new research suggests. The
prostate specific antigen, or PSA, is a commonly measured blood marker
in men with prostate cancer. In the new study, patients who had been treated
for prostate cancer were at increased risk for death if it took less than
three months for the PSA level to double.
Dr. Anthony V. D'Amico,
of Brigham and Women's Hospital in Boston, and colleagues followed more
than 8000 men treated for prostate cancer between 1998 and 2002. They
report in the Journal of the National Cancer Institute that 154 patients
died during a follow-up period of around 7 years; 110 of the deaths were
due to prostate cancer. During follow-up, 12 percent of patients treated
with surgery and 20 percent of those treated with radiation had a PSA
doubling time of less than 3 months. Such patients were nearly 20 times
more likely to die of prostate cancer than patients with longer doubling
times. Based on these findings, the authors propose that a doubling time
of less than 3 months could be used as a surrogate end point in prostate
cancer studies. In a related editorial, Dr. Howard M. Sandler and Dr.
Michelle L. DeSilvio note that by using doubling time of less than 3 months
as an end point instead of survival, clinical trials could be shortened
and trial results evaluated more rapidly. Both editorialists are radiologists,
Sandler at the University of Michigan in Ann Arbor, and DeSilvio at the
American College of Radiology in Philadelphia.
[Top]
Prostate
Cancer Therapy May Help Older Men-(Reuters Health-18/09/2003)
Although underused,
aggressive treatments, such as complete removal of the prostate gland,
can improve the survival of older men with early prostate cancer, new
research suggests. Men younger than 60 years with early prostate cancer
are 25 times more likely than men age 70 years or older to undergo "radical"
surgery, the authors explain, perhaps because of a perception that older
men are unlikely to benefit from such therapy. Dr. Shabbir M.H. Alibhai
from University Health Network, Toronto, Ontario, Canada and colleagues
used a special statistical model based on past data to compare radical
surgery, radiation, and regular observation in older men with prostate
cancer. The new findings are published in the Journal of Clinical Oncology.
For most men over
age 65 with really early disease, regular observation seemed to produce
the best balance between increasing survival and not impairing quality
of life. For men with slightly more advanced disease, the best treatment
was less clear. Surgery seemed to be the best choice for men younger than
65 years, but it was unclear whether observation became the best option
starting at 65 years or 75 years. For otherwise healthy men with the most
advanced disease, surgery and radiation were equally effective methods
of improving survival in men up to 85 years of age. Overall, the benefits
of these potentially curative treatments were restricted to men without
a lot of other coexisting diseases.
"Based on all of
the data accumulating," Alibhai told Reuters Health, "I believe there
is a survival advantage to treating patients with either surgery or (radiation),
although the gains may be huge or more modest...given the uncertainty
of the data." "Many men aged 70 to 80 who are generally well or have well-controlled,
stable diseases such as diabetes, asthma, or hypertension, will benefit
from aggressive therapy for (serious) disease," Alibhai concluded. "I
believe we need to be more aggressive in treating this group of patients."
[Top]
Prostate
Cancer Treatment Gets Under the Skin-(Reuters Health-03/09/2003)
A new method of delivering
a prostate cancer drug under the skin is useful in maintaining low levels
of testosterone, a hormone that can cause frustrating symptoms and promote
the growth of cancer cells, new research shows. The drug, called leuprolide,
and others like it are used to ease the symptoms in men with advanced
prostate cancer, the authors note. Long-term delivery systems for leuprolide
can contribute greatly to patient compliance. Dr. Robert C. Tyler, from
Atrix Laboratories, Inc. in Fort Collins, Colorado, and associates studied
the safety and effectiveness of a new leuprolide delivery system in 90
men with prostate cancer. The LA-2575 system involves injection of leuprolide
mixed with a biodegradable polymer under the skin, where it forms a solid
depot. Over time, the depot gradually releases leuprolide into the patient's
bloodstream. Within 28 days of injection, nearly all of the men had testosterone
levels that were as low as those seen in men without testes-the glands
where testosterone is produced.
The most common side
effect related to treatment was hot flashes, the investigators report,
although the level of testosterone suppression did not influence the frequency
and severity of hot flashes. In contrast to treatments tested in the past,
the authors note, no patients treated with the LA-2574 system required
additional or alternate drugs to control their testosterone levels. LA-2575
injected at 112-day intervals during 8 months in men with prostate cancer
"was effective in producing and maintaining therapeutic suppression of
testosterone," the researchers conclude. "Additional research is needed
to determine whether the degree of testosterone suppression is linked"
to prostate cancer survival, they add.
[Top]
Vitamin
D Mimic May Improve Prostate Cancer Therapy-(Reuters Health-27/08/2003)
Treating prostate
cancer cells with a vitamin D-like compound appears to make them more
susceptible to the destructive effects of radiation, lab experiments show.
If this research holds up, pretreating prostate cancer patients with the
vitamin D "analog" could offer two benefits. It might allow the radiation
dose to be reduced, resulting in fewer side effects, or it could enhance
the effectiveness of standard dose radiation. However, "our findings first
need to be verified in animal studies followed by testing in humans,"
Dr. Constantinos Koumenis, from Wake Forest University in Winston-Salem,
North Carolina, told Reuters Health. The analog, which is produced by
Abbott Labs under the name Zemplar, is already approved by the FDA as
treatment for an overactive parathyroid gland "which should expedite testing
in prostate cancer patients," Dr. Koumenis noted. Optimistically, "testing
in humans could begin in a year," he added.
In the new study,
the researchers irradiated human prostate cancer cells that were exposed
to Zemplar, calcitriol (the active form of vitamin D), or were untreated.
The results are published in the online issue of the British Journal of
Cancer. The killing effect of radiation was stronger when the cells were
first exposed to Zemplar or calcitriol. In addition, the enhanced destruction
was fairly selective, leaving normal prostate cells relatively unscathed.
"The reason for the synergy between Zemplar and radiation is unclear,"
Dr. Koumenis noted. However, vitamin D by itself has been shown to slow
the growth of prostate cancer cells, he added. Although calcitriol was
effective in these experiments, it has one major drawback: it tends to
cause high calcium levels in the blood, which can lead to a number of
problems. Zemplar, by contrast, appears much less likely to produce this
metabolic disturbance.
[Top]
Standard
Prostate Cancer Test Is Inaccurate, Study Says-(ET-23/07/2003)
The standard PSA
blood test used to screen for prostate cancer is highly inaccurate, failing
to flag eight of every 10 men under 60 who are later diagnosed with the
disease, according to a new study that promises to amplify debate over
medical practices concerning the common male malignancy. The study, in
this week's New England Journal of Medicine, said the results of the blood
test could be dramatically improved by simply lowering the threshold for
what is considered a problematic result to 2.6 from four on the PSA scale,
which measures how many billionths of a gram of prostate-specific antigen
are present in a milliliter of blood. But if the lower level were to become
the accepted new threshold, it would likely lead to far more prostate
biopsies -- operations in which small pieces of the prostate are extracted
to determine definitively whether cancer is present. Although that could
have benefits in early warning in some cases, most men who undergo a biopsy
after a PSA test don't have cancer and there is no hard evidence that
early detection of prostate cancer decreases mortality. In fact, critics
say, early detection can lead to unnecessary treatment.
About three- quarters
of the men over 50 in the U.S. have been screened by a PSA. The authors
-- from research centers in Boston, Chicago and St. Louis -- report that
the current standard for recommending a biopsy using a PSA test misses
82% of the cancers in men under 60 and two-thirds of the cases in men
over 60. Lead author Rinaa Punglia, a radiation oncologist at Brigham
and Women's Hospital in Boston, said past studies have indicated the PSA
test is near perfect. But her study found the test suffers from verification
bias, which is the simple fact that not every man who undergoes a PSA
test then has a biopsy performed, which is the gold standard for identifying
prostate cancer. Without knowing whether men who were screened out by
the PSA might have cancer, it is difficult to determine the true accuracy
of the PSA test.
The researchers used
a mathematical model to adjust for verification bias. Those results indicate
that lowering the threshold for recommending a biopsy to 2.6 can double
the cancer detection rate in men under 60 to 36% from 18%. For older men,
the rate increases to 60% from 35%. Howard Parnes, chief of the prostate
and urologic research group at the National Cancer Institute, praised
the work of the researchers, but said lowering the PSA standard has risks,
including subjecting more men to biopsies that are likely to be negative.
In the study, which examined cases involving 6, 691 men enrolled in a
prior study done at the Washington University College of Medicine, about
7% of the men fell in the PSA range of 2.6 to 4. In addition, Dr. Parnes
said many men may have localized cases of prostate cancer that don't pose
a serious health risk. "This is not to say PSA screening is only picking
up indolent, unimportant disease," he said. "I'm making a point that there
is a lot of prostate cancer out there and to me that is one of the hidden
downsides. When you screen for this disease, some of the disease you pick
up doesn't need to be found. It is not destined to pose a threat."
As evidence of the
controversy surrounding PSA testing, the journal also published a companion
editorial that rebuffs the suggestion of the study authors that the PSA
standard be lowered. The editorial authors, from the Erasmus Medical Center
in Rotterdam, the Netherlands, warned that lowering the PSA threshold
for performing a biopsy will increase the rate of overdiagnosis and, potentially,
overtreatment. The editorial authors said any decision to lower the PSA
threshold should come from clinical trials designed to show whether men
who undergo screening are less likely to die of prostate cancer than those
who don't. Two such trials are under way -- one in the U.S. and another
in Europe -- but results aren't expected for several years. Many experts
say the screening decision should be made by the patient. Some men may
be happy not knowing if they have the disease, particularly if there is
no evidence early detection will reduce their risk of death. However,
many doctors believe early detection can save lives, and at the very least,
the condition can be monitored to make sure it isn't worsening. For men
considering whether to undergo screening, the cancer prevention and control
division of the Centers for Disease Control and Prevention has recently
published a prostate cancer screening decision guide. It is available
at the agency's Web site: www.cdc.gov/cancer/prostate/decisionguide/index.htm
[Top]
Flaxseed-Rich
Diet Blocks Prostate Cancer Growth and Development in Mice-(ET-15/07/2003)
A diet rich
in flaxseed seems to reduce the size, aggressiveness and severity of tumors
in mice that have been genetically engineered to develop prostate cancer,
according to new research from Duke University Medical Center. And in
3 percent of the mice, the flaxseed diet kept them from getting the disease
at all. "We are cautiously optimistic about these findings," said Wendy
Demark-Wahnefried, Ph.D., associate professor, division of urology and
senior author of the study that appears in the November 2002 issue of
the journal Urology. "The amount of flaxseed given to each mouse was 5
percent of its total food intake, which would be a very difficult amount
for humans to eat, but it does signal that we are on the right track and
need to continue research in this area." According to Demark-Wahnefried,
planned clinical trials must be completed before it can be concluded that
dietary flaxseed is a useful protective against prostate cancer in humans.
The research was
sponsored by the National Institute on Aging, the National Cancer Institute
and the Committee for Urologic Research Education and Development at Duke
University Medical Center. Clinical studies by other researchers have
suggested that dietary fiber reduces cancer risk, and omega-3 fatty acids
also have shown a protective benefit against cancer. Flaxseed is the richest
plant source of omega-3 fatty acids and is high in fiber. Also, flaxseed
is a source of lignan, a specific family of fiber-related compounds that
appear to play a role in influencing both estrogen and testosterone metabolism.
Since testosterone may be important in the progression of prostate cancer,
lignan could help inhibit the growth and development of the disease.
In the Duke study,
135 mice genetically engineered to develop prostate cancer were divided
into a control group and an experimental group. The experimental group
received a regular mouse diet, but 5 percent of the diet was in the form
of flaxseed. Half of the mice in both groups were fed their respective
diets for 20 weeks and the remainder for 30 weeks. At the 20- and 30-week
end points, the mice were autopsied to check for tumor growth and progression
of the disease to other organs. "Tumors in the untreated control group
were twice the size of tumors in the flaxseed group," said Xu Lin, M.D.,
research associate, division of urology and lead author of the study.
"The tumors were also less aggressive in the flaxseed group, and two of
the mice in the flaxseed group did not develop prostate cancer at all.
The rates of apoptosis (tumor cell death) were also higher in the flaxseed
group. And while it was not statistically significant, the flaxseed group
had fewer rates of the cancer spreading to other organs. " While the results
are promising, the researchers say they are not surprising.
The study is the
third in a series by the Duke Medical Center researchers to show the benefits
of flaxseed in reducing the growth and development of prostate cancer.
The first study, published in July 2001 in Urology, demonstrated that
a low-fat diet supplemented with flaxseed was associated with slower tumor
growth. In this pilot study, 25 men with prostate cancer began adding
ground flaxseed to their diets for 34 days. At the end of the study, the
men saw a drop in testosterone levels and a trend toward lower prostate
specific antigen (PSA) levels, a marker for prostate cancer. The diet
also was tolerated well and gave the authors hope for this dietary intervention.
The second study, published in the November-December 2001 issue of Anticancer
Research, examined the effect lignans have on prostate cancer cell lines.
This study showed that flaxseed-derived lignans inhibited the growth of
three distinct human prostate cancer cell lines through hormonally dependent
and independent mechanisms.
"So far we have observed
the suppression of prostate cancer in humans, mice and at the cellular
level," said Lin. "It's not a fluke or a coincidence. It's an encouraging
line of research." Demark-Wahnefried adds, "Our results are encouraging.
However, before we can truly state that flaxseed is beneficial in humans,
larger well-controlled trials are needed. The National Cancer Institute
has provided us with the support to conduct a randomized clinical trial
in 160 men with prostate cancer that will examine whether a low-fat diet,
flaxseed supplementation or a combination of low-fat diet and flaxseed
supplementation will be most effective in stopping prostate cancer cells
from dividing. That trial is currently under way."
[Top]
Eat
Your Whey: It May Protect against Prostate Cancer-(ET-15/07/2003)
New research
suggests that whey, a liquid byproduct from cheese production, may play
a role in helping prevent prostate cancer. When Ohio State University
food scientists treated human prostate cells in the lab with whey protein,
cellular levels of the antioxidant glutathione increased. Antioxidants
such as glutathione have been shown to control cancer-causing free radicals.
Cancer researchers suspect that the accumulation of free radicals plays
a role in the development of prostate cancer. In the current study, the
Ohio State scientists found that treating prostate cells with whey protein
elevated glutathione levels in the cells by up to 64 percent. "The buildup
of free radicals is associated with the onset of many chronic illnesses,
such as heart disease and cancer," said Joshua Bomser, a study co-author
and an assistant professor of food science and technology at Ohio State.
"And human prostate tissue is particularly susceptible to oxidative stress."
The study appears
in the journal Toxicology in Vitro. Bomser conducted the study with Kyle
Kent, a graduate student in the department of food science at Ohio State,
and W. James Harper, the J.T. "Stubby" Parker Chair in Food Science and
Technology, also at the university. The researchers treated human prostate
cells with two concentrations of whey protein for 48 hours and then measured
the levels of glutathione in the cells. Whey contains the amino acid cysteine
-- a key ingredient for making glutathione in the body. Surprisingly,
both treatments increased the levels of glutathione considerably. The
larger dose increased glutathione by 64 percent and the smaller dose,
which was half of the larger dose, increased levels by 60 percent. "The
small difference in glutathione levels between the two whey concentrations
suggests that it may not take much whey protein to get an effect in the
prostate cells," Bomser said. "In diseases like cancer, there's usually
a reduction in the body's overall capacity to deal with oxidative stress,"
he continued. "Keeping antioxidant levels elevated through diet and supplementation
may prevent the development of chronic disease."
The researchers treated
another batch of prostate cells with casein, the major protein found in
cheese. Casein doesn't contain the key ingredient for manufacturing glutathione,
and, as expected, glutathione levels in these cells did not increase.
"Unlike casein, whey proteins are rich in cysteine, an amino acid that
increases glutathione in the prostate," Kent said. "Cheese contains various
proteins that can influence the levels of different antioxidants in prostate
cells," Kent continued. "But cysteine is the amino acid that helps create
healthy glutathione levels in the prostate, and glutathione helps keep
free radicals under control." The researchers warn that simply eating
cheese won't ensure an increase in glutathione levels, because cysteine
is contained in the whey that's separated from cheese early in the cheese-making
process. But cysteine is also found in foods such as poultry, wheat, broccoli
and eggs. While whey protein supplements have become popular among body
builders, Bomser and his colleagues say that most people living in the
United States already get plenty of protein in their diet, so adding an
additional protein shake isn't necessary. They stress the importance of
a well balanced diet, adding that whey is a complete protein, one that
has the right amount of amino acids that are essential to our bodies.
[Top]
Bad
Gene Ups Prostate Cancer Risk in Black Men- (HealthDayNews-09/07/2003)
A gene called macrophage
scavenger receptor 1 (MSR1) plays an important role in the development
of prostate cancer in black American men. So says a study in the July
1 issue of Cancer Research. The finding comes from a larger project called
the Flint Men's Health Study, which is meant to identify prostate cancer
risk factors in black American men. "African-American men have the highest
incidence of prostate cancer in the world. The severity is higher and
they tend to die more quickly after diagnosis," study author Dr. Kathleen
Cooney, an associate professor of internal medicine at the University
of Michigan Comprehensive Cancer Center, says in a statement. "We don't
know why this is, but part of the difficulty is that African-American
men are underrepresented in most genetics studies," Cooney says.
This study included
black men, aged 40 to 79, living in Flint, Mich. DNA samples were collected
from 134 men diagnosed with prostate cancer and 340 men without the disease.
After analyzing the DNA samples, the researchers concluded that rare germ-line
MSR1 mutations were associated with an increased risk of prostate cancer.
Previous studies found the same association in white men. "This study
adds to an expanding body of evidence in support of germ-line MSR1 mutations
as risk factors for prostate cancer. Although our study was modest in
size, the public health burden of prostate cancer in the African-American
community warrants further attention to potential genetic risk factors,"
lead author Dr. David Miller, a urology resident at the University of
Michigan Medical School, says in a news release.
[Top]
First
Prostate Cancer Prevention Drug Found, but Not All Men Benefit- (NIH/National
Cancer Institute-02/07/2003)
Men who took finasteride,
a drug that affects male hormone levels, reduced their chances of getting
prostate cancer by nearly 25 percent compared to men who took a placebo,
according to results of a national study released today online by the
New England Journal of Medicine. These findings resulted in the early
closing of the study, called the Prostate Cancer Prevention Trial (PCPT),
which was coordinated by a network of researchers called the Southwest
Oncology Group (SWOG) and funded by the National Cancer Institute (NCI).
The 10-year trial, involving nearly 19,000 participants nationwide, was
originally scheduled to end in May 2004. "Finasteride is the first drug
found to reduce the risk of prostate cancer," said Ian Thompson, M.D.,
University of Texas Health Sciences Center, who led the study. "The drug
worked for men at low risk for prostate cancer, as well as those at high
risk." Age, PSA level at enrollment, family history of prostate cancer,
and race or ethnicity did not affect the drug's ability to prevent the
disease.
"There is a cautionary
note," said Thompson. "Men in the study who developed prostate cancer
while taking finasteride were more likely to have high-grade cancers,
which, when found in the general population, may spread quickly even if
the tumors are small. But, more than 97 percent of men who did develop
prostate cancer during this study had early-stage cancers, which are most
often curable." The reason men on finasteride had more high-grade tumors
is currently unknown, but the researchers are studying several possibilities.
The drug affects the appearance of prostate cancer cells, and this may
lead to a false estimate of tumor grade, which is determined visually
by a pathologist. Another possible explanation being examined is whether
finasteride truly causes more aggressive tumors to develop--either by
preventing only low-grade tumors, or by making the prostate gland more
favorable to aggressive tumors.
Prostate cancer is
the most common cancer in men, after skin cancer, and will affect nearly
221,000 men in the United States this year. About 29,000 men will die
of the disease. The disease--as well as its treatment, which sometimes
leads to impotence, urinary incontinence, and other problems--causes a
significant health burden for men.
Finasteride was approved
in 1992 at a 5 milligram (mg) dose for treating benign prostatic hyperplasia
(BPH), a noncancerous enlargement of the prostate that can cause problems
with urine flow. A few years later, the drug was approved at a 1 mg dose
to treat male pattern baldness. In PCPT, healthy men ages 55 and older
were randomly assigned to take either 5 mg finasteride or placebo daily
for seven years. Neither the participants nor their doctors knew which
men were assigned to take which pills. This type of study, called a double-blind,
placebo-controlled trial, is considered the scientific gold standard for
determining if an intervention works. Men chosen for PCPT showed no evidence
of prostate cancer at the start of the trial. To enter the study, men
needed to have a normal digital rectal exam (DRE) and a prostate specific
antigen (PSA) level of 3 nanograms/milliliter (ng/ml) or less. These tests
were repeated annually. The participants also agreed to have a prostate
biopsy after they had participated for seven years. At the time the trial
ended, about 9,000 men had undergone biopsies.
PCPT researchers
will continue to monitor the men who participated in the trial at the
more than 200 sites around the country. "What these men have already given
us is priceless," said Thompson. "But, we will continue to learn much
more. The participants provided us with blood and biopsy samples, and
this repository of biological materials will prove invaluable in learning
more about the molecular changes that happen as prostate cancer develops."
On March 3, 2003, the Data and Safety Monitoring Committee, an independent
body that periodically examined the study, advised that the trial be closed
early. The recommendation came because data already collected were sound,
and the conclusions were extremely unlikely to change with the addition
of more data.
By the close of the
study, prostate cancer had been found in about 18 percent of the men who
took finasteride, or 803 men out of 4,368. About 24 percent of men who
took placebo, or 1,147 men out of 4,692, also had been diagnosed with
prostate cancer. Many of the men with cancer had normal DREs and PSA levels,
and the disease was found only because the trial required an end-of-study
biopsy. Despite the fact that men taking finasteride had fewer prostate
cancers overall, they had a greater proportion of high-grade prostate
cancers. Overall, 6.4 percent of men on finasteride (280 men out of 4,368)
had high-grade tumors. For men on placebo, 5.1 percent (237 men out of
4,692) had high-grade cancers.
Having a low PSA
level did not correlate with the development of aggressive tumors--some
of the men in both groups of the trial had high-grade disease despite
PSA levels that would not have been a concern if the participants had
received routine screening outside of the trial. "Although a larger percentage
of men taking finasteride had tumors that appeared to be more aggressive
to a pathologist, we do not know if those tumors will act biologically
aggressive," said Ford. "We will follow these men long term to determine
whether a cancer that looks high grade in a man taking finasteride correlates
medically with aggressive disease."
The researchers regularly
monitored participants for side effects. Compared to men on placebo, more
men taking finasteride experienced sexual side effects at some point during
the study. On the other hand, urinary symptoms were reported by more men
taking placebo. "PCPT and its findings mark a milestone for the field
of cancer prevention, and we will continue to learn more in the years
to come," Ford said. "Finasteride's ability to prevent prostate cancer
has the potential to reduce the health care burden for this very common
disease. The next time men see their doctors, they may want to talk to
them about these findings."
Finasteride is just
one agent the NCI has been studying to prevent prostate cancer. Another
large prevention study currently underway, the Selenium and Vitamin E
Cancer Prevention Trial, or SELECT, is determining if these two dietary
supplements can protect against prostate cancer. SWOG, the same group
that coordinated PCPT, is conducting the SELECT study for NCI. "Men can
take finasteride and still participate in SELECT," said Charles A. Coltman
Jr., M.D., chairman of SWOG and director of the San Antonio Cancer Institute
in Texas.
[Top]
Too
Much Zinc Ups Prostate Cancer-(HealthDayNews-02/07/2003)
Men who overdose
on zinc supplements more than double their risk of prostate cancer, a
government study finds. The researchers looked at 46,974 men who were
involved in the Health Professionals Follow-Up study, and the increased
risk was seen in those who took more than 100 milligrams a day of zinc
supplements or used zinc supplements for more than 10 years. The report
appears in the July 2 issue of the Journal of the National Cancer Institute.
It's an important finding because prostate cancer is the second leading
cancer killer for American men, taking 30,000 lives a year. And 30 percent
to 40 percent of all men take one supplement or another, says study author
Dr. Michael F. Leitzmann, an epidemiological investigator at the National
Cancer Institute.
Zinc has long been
a target of prostate cancer research because it is found in high concentrations
in the prostate, but studies of its effects on malignancy have gotten
mixed results. One study released four years ago found an association
between daily doses of zinc and a reduced risk of the cancer. There isn't
necessarily a conflict between the two trials, says Dr. Janet Stanford,
a research professor of epidemiology at the Fred Hutchinson Cancer Research
Center in Seattle and a leader of the earlier study. "Our study was not
designed to assess supplement use," Stanford says. The new study is "intriguing,"
she says, and "does raise a question about the role of zinc in prostate
cancer. But it is not the basis for making decisions."
Leitzmann agrees,
noting his results might not conflict with those from the earlier study,
in part because the two trials used entirely different methods. The older
study asked men with prostate cancer if they had taken zinc supplements
and compared their answers with cancer-free men. The new study followed
men who started out cancer-free for 14 years, asking about their zinc
intake. The important point is that the risk was concentrated in men who
took the largest amounts of zinc for the longest time, Leitzmann says.
No increased risk was found in men who took up to 100 milligrams a day.
But those who took more than that amount daily were 2.29 times more likely
to develop the cancer than those who took less. And the risk was 2.37
times greater for men who took zinc supplements for 10 or more years.
Zinc is known to increase blood levels of insulin-like growth factor and
testosterone, both of which are directly related to prostate cancer, Leitzmann
says. It's possible malignancy occurs because high levels of zinc increase
the growth rate of slow-growing prostate cancers, he says. Not much is
known about modifiable risk factors for prostate cancer, Leitzmann says.
The best known risk factors are increasing age, a family history, and
race, with blacks at higher risk. Even with the latest findings, the evidence
that avoiding zinc supplementation might reduce prostate cancer risk "overall
is not very compelling," Leitzmann says. "This one study cannot conclusively
answer that question." But one obvious implication is that men "should
avoid supplements that contain multiple amounts of the recommended dietary
amounts," Leitzmann says.
[Top]
New
MRI Able to Pinpoint Smaller Tumors-(AP-18/06/2003)
An enhanced type
of MRI can detect much smaller tumors than ever before - some tinier than
a pea - in an advance that could open a new age in diagnosing cancer without
surgery, researchers say. The experimental technique examines the lymph
nodes for signs of spreading cancer. Doctors already routinely use MRIs
to check the lymph nodes to see whether cancer that originated somewhere
else in the body - say, in the breast or the prostate gland - is spreading.
But the enhanced technique proved superior to conventional MRIs when tested
with cancer that had spread from the prostate. And the leader of the research,
Dr. Mukesh Harisinghani, said his team has also had preliminary success
using the approach to detect the spread of breast, testicular, bladder
and kidney cancer.
In the prostate study,
the technique found 63 cancerous lymph nodes in 33 patients. Conventional
magnetic resonance imaging, or MRI, would have missed 71 percent of the
nodes, and the spreading cancer would have gone undetected in nine patients.
"Even if it only works this well for prostate cancer, it's a significant
advance," said Dr. Jeffrey Brown, a radiologist at Washington University
in St. Louis. Earlier detection of spreading prostate cancer would allow
more aggressive treatment sooner, help doctors track the response, and
spare some patients unnecessary removal of the prostate gland or lymph
nodes.
About 200,000 prostate
cancer cases are diagnosed each year, and 32,000 people die from it. The
Food and Drug Administration is considering whether to approve the new
technique. It is unclear when the FDA might decide. Dr. Samuel Wickline,
who studies imaging at Washington University, said this method and others
like it will eventually "allow us to diagnose things that you can't even
see with any imaging" now in use. The study, funded partly by the National
Cancer Institute, was carried out by Massachusetts General Hospital in
Boston and University Medical Center in Nijmegen, the Netherlands. The
findings appear in New England Journal of Medicine.
The method relies
on minuscule magnetic particles, known as nanoparticles, to enhance an
MRI. Acting like a television's contrast dial, the injected particles
collect in the immune system's lymph nodes and create a clearer separation
between dark and light areas in the image. Imaging systems have never
reliably shown tumors this small before anywhere in the body. Up to now,
the smallest tumors detectable by MRI have been about four-tenths of an
inch - the size of a fingernail. Conventional MRI uses a magnetic field,
which allows doctors to see enough only to gauge the size of lymph nodes.
Nodes bigger than four-tenths of an inch are generally considered cancerous;
however, they are not always cancerous, while some smaller nodes are.
The new technique shows detail within the nodes that reveals cancer's
presence.
The researchers gave
patients an imaging agent known as lymphotropic superparamagnetic nanoparticles,
which are specks of iron oxide less than a billionth of an inch across.
Normally, the liver sucks up imaging agents before they reach the lymph
nodes, but these particles are so small, they seep into the lymph system.
The technique appeared to work in cancerous lymph nodes from two-tenths
to four-tenths of an inch, which would normally go unnoticed with regular
MRI. It detected 96 percent of cancerous nodes that size, compared with
a detection rate of 29 percent for regular MRI, and it found 41 percent
of cancerous nodes smaller than two-tenths of an inch, which are invisible
to conventional MRI. When spreading cancer has already reached the lymph
nodes, doctors typically order radiation or hormonal treatments. The researchers
did not report any major side effects from the imaging agent. "I would
anticipate that it's going to get approved, and I would anticipate that
it's going to be a big seller," said Dr. Otis Brawley, a cancer specialist
at Emory University in Atlanta.
[Top]
Protein
Found Key in Prostate Cancer Spread-(Reuters Health-17/06/2003)
A protein
found in normal cells and some tumor cells may help block prostate cancers
from spreading, according to early study findings. In work with human
tissue samples, researchers had previously found that the protein, dubbed
RKIP, existed in average to high levels in normal prostate cells and in
prostate tumors that had not spread -- or metastasized -- to other parts
of the body. In contrast, RKIP was nearly absent in tumor cells that had
spread. Now, in work published in the Journal of the National Cancer Institute,
the same researchers found that adding RKIP back to metastatic prostate
cancer cells rendered them less adept at spreading. Dr. Zheng Fu and her
colleagues focused on RKIP after earlier work had shown the protein appeared
to be under-expressed in prostate tumor cells that had broken off and
spread.
"We found RKIP at
normal to high levels in normal prostate cells and in cells from the primary
tumor," study co-author Dr. Evan T. Keller of the University of Michigan
said in an interview with Reuters Health. "But it was virtually absent
in all the metastatic cells." To discover what role RKIP might play in
cancer's spread, the researchers genetically engineered metastatic prostate
cancer cells to again produce RKIP. These genetically engineered cells
were then injected into one group of mice. Unaltered cells were injected
into another group of mice for comparison. "By putting RKIP back, we ended
up with (an) over 70 percent reduction in metastasis," Keller said. "It
didn't affect the growth rate of the tumor itself. Instead, it somehow
inhibits the cells' ability to invade blood vessels."
For cancer cells
to spread to a new site, they must first be able to commandeer blood vessels
so that they will have fuel to grow, Keller explained. The new research
could lead to therapies to block tumors from metastasizing, according
to Keller. "Perhaps with gene therapy we could restore RKIP to these cells,"
he said. "Or if we understand the signaling pathways that this gene turns
on or off, we could inhibit those pathways." An editorial published with
the report notes: "The molecular understanding of cancer metastasis has
taken yet another step forward with findings published in this issue of
the Journal." The results signal "a major step toward controlling the
most deadly attribute of cancer cells," write Drs. Danny R. Welch, of
the University of Alabama at Birmingham, and Kent W. Hunter, of the National
Cancer Institute.
[Top]
Eat
Your Whey: It May Protect against Prostate Cancer-(ET-28/05/2003)
New research
suggests that whey, a liquid byproduct from cheese production, may play
a role in helping prevent prostate cancer. When Ohio State University
food scientists treated human prostate cells in the lab with whey protein,
cellular levels of the antioxidant glutathione increased. Antioxidants
such as glutathione have been shown to control cancer-causing free radicals.
Cancer researchers suspect that the accumulation of free radicals plays
a role in the development of prostate cancer. In the current study, the
Ohio State scientists found that treating prostate cells with whey protein
elevated glutathione levels in the cells by up to 64 percent. "The buildup
of free radicals is associated with the onset of many chronic illnesses,
such as heart disease and cancer," said Joshua Bomser, a study co-author
and an assistant professor of food science and technology at Ohio State.
"And human prostate tissue is particularly susceptible to oxidative stress."
The study appears in the journal Toxicology in Vitro.
Bomser conducted
the study with Kyle Kent, a graduate student in the department of food
science at Ohio State, and W. James Harper, the J.T. "Stubby" Parker Chair
in Food Science and Technology, also at the university. The researchers
treated human prostate cells with two concentrations of whey protein for
48 hours and then measured the levels of glutathione in the cells. Whey
contains the amino acid cysteine -- a key ingredient for making glutathione
in the body. Surprisingly, both treatments increased the levels of glutathione
considerably. The larger dose increased glutathione by 64 percent and
the smaller dose, which was half of the larger dose, increased levels
by 60 percent. "The small difference in glutathione levels between the
two whey concentrations suggests that it may not take much whey protein
to get an effect in the prostate cells," Bomser said. "In diseases like
cancer, there's usually a reduction in the body's overall capacity to
deal with oxidative stress," he continued. "Keeping antioxidant levels
elevated through diet and supplementation may prevent the development
of chronic disease."
The researchers treated
another batch of prostate cells with casein, the major protein found in
cheese. Casein doesn't contain the key ingredient for manufacturing glutathione,
and, as expected, glutathione levels in these cells did not increase.
"Unlike casein, whey proteins are rich in cysteine, an amino acid that
increases glutathione in the prostate," Kent said. "Cheese contains various
proteins that can influence the levels of different antioxidants in prostate
cells," Kent continued. "But cysteine is the amino acid that helps create
healthy glutathione levels in the prostate, and glutathione helps keep
free radicals under control." The researchers warn that simply eating
cheese won't ensure an increase in glutathione levels, because cysteine
is contained in the whey that's separated from cheese early in the cheese-making
process. But cysteine is also found in foods such as poultry, wheat, broccoli
and eggs. While whey protein supplements have become popular among body
builders, Bomser and his colleagues say that most people living in the
United States already get plenty of protein in their diet, so adding an
additional protein shake isn't necessary. They stress the importance of
a well balanced diet, adding that whey is a complete protein, one that
has the right amount of amino acids that are essential to our bodies.
[Top]
Families
Sought in Hunt for Male Cancer Genes-(Reuters-27/05/2003)
British scientists
launched a national hunt for families with a history of testicular or
prostate cancer to help in the search for genes related to the diseases.
They are looking for men who have three or more relatives who developed
prostate cancer before the age of 70 or who have two or more family members
with testicular cancer. By examining the genetic profiles of men with
the disease, they hope to identify genes that increase a man's risk of
developing the cancers. "Fifteen percent of prostate cancer and up to
30 percent of testicular cancer may be due to an inherited predisposition,"
Professor Colin Cooper of the Institute of Cancer Research, told a news
conference. "Genes are important because they provide targets for new
drugs and they help to determine the course of the disease," he added.
Scientists have discovered
genes involved in breast cancer, but the search for male cancer genes
has lagged behind. Six possible sites for prostate cancer genes and one
for testicular cancer have been identified, and researchers are hoping
the genetic studies will help them pinpoint the culprits. Cooper said
testicular is the most genetic of all cancers. A man with a brother who
has testicular cancer has an eight to 10-fold increase in the chances
of getting it himself. Men with a family history of either testicular
or prostate cancer can contact their family doctor or a specialist at
the Institute for Cancer Research (www.icr.ac.uk) if they want to take
part in the study.
[Top]
Broccoli
Could Be Prostate Cancer Fighter-(HealthScoutNews-14/05/2003)
It's no secret that
men who eat lots of vegetables seem more likely to avoid prostate cancer,
but researchers now think a chemical in broccoli and cauliflower could
help doctors treat the disease, too. No one has tested the chemical on
humans yet, however, and it may take years to turn it into a usable drug.
"It's interesting early work, but it's a long way from something going
on in a test tube to exactly what goes on in humans," says Dr. Durado
Brooks, director of prostate and colorectal cancers for the American Cancer
Society. Prostate cancer is the most commonly diagnosed cancer among men
in the United States and kills about 30,000 each year, according to the
National Prostate Cancer Coalition.
A number of treatments
are available, but side effects commonly include incontinence and impotence.
Prostate cancer rates are lower in countries where people eat plenty of
fruits and vegetables, although the exact link between diet and the disease
isn't clear, Brooks says. Researchers at the University of California
at Berkeley decided to investigate the cancer-fighting effects of chemicals
in cruciferous vegetables such as broccoli, cauliflower, kale, Brussels
sprouts and cabbage. "We realized that what was missing was a comprehensive
study of how these natural compounds affect the growth and function of
reproductive cancer cells," says study co-author Gary Firestone, a professor
of molecular and cell biology at the University of California at Berkeley.
The researchers found
that a chemical known as 3,3'-diindolylmethane (DIM), a byproduct of eating
cruciferous vegetables, appeared to prevent the growth of breast cancer
cells. They next turned to prostate cancer cells. The researchers found
that prostate cancer cells treated with DIM grew 70 percent slower than
untreated cells. Their research will appear in the June 6 issue of the
Journal of Biological Chemistry. The chemical appears to prevent cancer
cells from receiving signals from the hormone testosterone, Firestone
says. That, in turn, prevents the cells from growing. By contrast, traditional
hormone therapy for prostate cancer patients is designed to prevent testosterone
from getting to the cells in the first place. "You cut off the signal
that makes the prostate cancer cells grow," Firestone says. It's possible
that the chemical could be used in combination with hormone therapy, Firestone
says, letting doctors dampen the side effects of lowering testosterone
levels. Producing drugs from the vegetables may be easy and inexpensive,
he adds: "There's a lot of broccoli and cabbage, and you should be able
to obtain a lot of this chemical at a very cheap price."
However, Brooks says
hormone treatment is much less common than other prostate cancer treatments.
Surgery and radiation are the usual treatments. Research into chemicals
derived from vegetables may be more important in terms of prevention,
says Satya Narayan, an associate professor of anatomy and cell biology
at the University of Florida. "These compounds may be of greater importance
for prostate cancer prevention at the early stages of the prostate cancer
development, instead of at the later stages when the cancer is advanced."
But it's still not clear how many vegetables men would need to eat to
protect themselves from getting prostate cancer in the first place.
[Top]
Research
Helps Prostate Cancer Victims-(ET-07/05/2003)
Scientists
at Baylor College of Medicine are quickly catching up with a killer. They
have discovered a gene that could help destroy prostate cancer before
it strikes 30,000 men this year -- men like Tony Masraff. "I'm tired,
in a way, of doctors and people talking about, 'Oh it's a slow-growing
cancer. You don't need to worry about it as much,'" Masraff said. There
has not been a wealth of research for prostate cancer, so its victims
have few options -- surgery or chemotherapy -- and they often cause impotence.
"They belittle sexual dysfunction, the incontinence," Masraff said. So
Masraff, a restaurateur in the Galleria area, launched his own battle
to raise money. "To me, my quality of life was much more important than
how long I'm going to live," Masraff said. Since research relies on money,
Masraff wanted to make a difference, one step at a time. "I'll run the
marathon. Well, I've never run in my life," Masraff said. With overwhelming
support, he finished the race, and raised $100,000 for prostate cancer
research. It helped Dr. Timothy Thompson and his team at Baylor.
They said that they
have discovered a gene with a protein that kills cancer and tells the
body to keep killing it. "It's almost like calling in armed forces. This
gene recruits other troops if you will, other immune cells, to come in
and use the body's own response mechanisms to eliminate cancer," Thompson
said. Thompson's research is so promising that clinical trials will begin
next year. Anyone interested in becoming a part of the trials should contact
Baylor College of Medicine at (713) 799-8718 to get on the list for phase
one. Masraff has posted information online about prostate cancer and research.
For more information, visit www.masraffs.com/prostatecancer.htm
[Top]
Viagra
May Restore Erections After Prostate Surgery-(Reuters Health-28/04/2003)
Men who undergo
surgery for prostate cancer may ward off problems with erections by taking
Viagra every night for nine months after surgery, researchers said. According
to the report, men who took nightly Viagra (sildenafil) for nine months
after having their prostate removed in a surgery known as radical prostatectomy
were more than seven times as likely to regain their normal, pre-operative
erectile functioning as men who received a placebo, or inactive, drug.
These findings suggest that along with treating erectile dysfunction,
Viagra can also prevent the condition in the first place, study author
Dr. Harin Padma-Nathan of the University of Southern California in Los
Angeles told Reuters Health. "The results of this study are so dramatic
that every man undergoing (radical) prostatectomy should consider this
if he is interested in preserving erections," Padma-Nathan said. Although
newer forms of the surgery do not involve cutting the nerves leading to
and from the penis, which are crucial to erections, even this "nerve-sparing"
radical prostatectomy can injure these nerves, causing problems.
During the procedure,
the researchers asked 23 and 28 men to take 50 milligrams and 100 milligrams
of Viagra, respectively, every night for nine months staring four weeks
after surgery. Another 25 men took a placebo during the same time period.
None of the men knew whether they were taking Viagra or placebo. All of
the men had normal erectile function before surgery. After nine months
of treatment, study participants then spent another eight weeks without
taking any medication. Padma-Nathan and his colleagues discovered that
27 percent of men who had received Viagra -- regardless of dose -- had
regained full erectile functioning, equal to what they reported before
undergoing surgery, a finding seen in only 4 percent of men given placebo.
These findings, presented during the annual scientific meeting of the
American Urological Association in Chicago, suggest that Viagra "prevents
the degeneration of erection function following the surgery," Padma-Nathan
said in an interview. And the difference between using and not using Viagra
was "dramatic," he added. "If you don't do anything, it's not very good,"
he said. "Intervention certainly made it a whole lot better."
Typically, men take
either 50 or 100 milligrams of Viagra to treat erectile dysfunction, and
the current findings suggest that the lower dose is just as effective
at preventing the problem, he added. Previous research in animals suggests
that Viagra, along with increasing blood flow to the penis, may actually
help repair nerves that have been damaged during surgery, Padma-Nathan
noted. None of the men taking Viagra reported any serious side effects
from the medication, and only two dropped out of the study, citing headache
and fatigue, the researcher said. Although taking Viagra every night for
nine months could be a significant expense for some patients, Padma-Nathan
noted that men who typically undergo radical prostatectomy start taking
Viagra after surgery and use it to treat erectile problems for the rest
of their lives. Given that the men included in this study were in their
mid-50s, that represents a long time to take the drug, he said. "It's
actually cheaper to use it continuously for nine months and stopping it
altogether than using it intermittently for a couple times a week for
the rest of their lives," Padma-Nathan said. The study was funded by Pfizer
Inc., maker of Viagra.
[Top]
Study
Suggests Western Diet Tied to Prostate Cancer-(Reuters Health-28/04/2003)
Prostate
cancer is 10 times more common in the United States than Japan and preliminary
research suggests that differences in diet may be a reason why. There
has been much speculation that the Western diet is a factor because when
Japanese men move to the U.S. and start eating plenty of high-fat burgers
and pizza and less soy, their risk of prostate cancer increases. "Within
one generation, the prostate cancer incidence begins skyrocketing," said
study author Dr. Leonard S. Marks, a clinical associate professor of urology
at the University of California at Los Angeles. In a new study at a meeting
of the American Urological Association in Chicago, Marks and colleagues
examined blood and prostate cancer tissue samples and compared health
data from 50 men who had undergone surgery to remove a cancerous prostate
gland. Half of the men lived in Japan, while the other half were Los Angeles
residents born in the U.S. to Japanese parents. As such, both groups had
similar genetic roots. But there were marked differences in what they
ate. The Japanese-American men reported eating a diet substantially higher
in animal fat. Not surprisingly, they also had a greater percentage of
body fat and higher triglyceride levels in their blood. The native Japanese
men ate more soy than the Japanese-American men. Soy has been thought
to possibly offer protection against prostate cancer. "Soy didn't protect
these men," Marks said, "but soy may be protecting many other men who
don't get prostate cancer in Japan."
While the prostate
cancer samples from the two groups appeared similar, detailed analysis
of the tumor cells' genetic material told another story. "Since the DNA
was arranged differently, there may be a gene-nutrient interaction responsible
for the differences," Marks said. "The cancers look the same but their
genesis appears to be different, and that may be a result of diet," he
told Reuters Health. Still, much more research is needed to explain why
prostate cancer rates vary widely around the world. "Does this study prove
why the differences are there? It doesn't," Marks said. "It's a first
step."
[Top]
Research
Sheds New Light On Why Some Prostate Cancers Become Untreatable-(Yahoo
News-28/04/2003)
Three new studies
by researchers at UC Davis Cancer Center provide new pieces to the puzzle
of why some prostate cancers become resistant to androgen suppression
therapy. The studies were presented Sunday afternoon at the 2003 annual
meeting of the American Urological Association. Of the nearly 190,000
men in the United States who develop prostate cancer every year, a substantial
proportion will require androgen suppression therapy to reduce levels
of male hormones-a treatment that can shrink prostate cancers or slow
their growth. Hormone suppression therapy eventually fails, however, as
prostate cancer cells adapt to an androgen-depleted environment, a state
known as androgen independence. When this happens, few treatment options
remain. Determining how androgen independence develops, and how the process
can be derailed, is a chief focus of prostate cancer research at UC Davis.
"If we could prevent androgen independence from happening, it would have
a dramatic impact on treatment and outcomes for prostate cancer," says
Ralph deVere White, chair of urology at UC Davis School of Medicine and
Medical Center and director of the UC Davis Cancer Center.
Two of the studies
presented report new information about p53's role in androgen independence.
Mutations in p53 are seen in two out of three prostate cancers that have
developed androgen independence. In one of the studies, deVere White and
his colleagues demonstrated that four particular p53 mutations -- G245S,
R248W, R273C and R273H -- facilitate androgen-independent growth in human
prostate cells. The researchers were able to grow the four mutant cell
lines in androgen-free conditions both in cell culture and in female laboratory
mice. In addition, the researchers successfully used siRNA technology
to target an siRNA molecule to the R273H mutation and down-regulate (suppress)
its activity -- suggesting that siRNA technology may have therapeutic
value in the treatment of hormone-independent prostate cancer. In a second
study, Clifford G. Tepper and his colleagues used microarray technology
to hunt for specific genes that contribute to androgen independence.
They reported that
over-expression of one gene, known as Id-1, is a feature of androgen-independent
tumors with p53 mutations. In order to identify Id-1, the researchers
profiled more than 12,000 genes. They found 21 that are over-expressed
in cells harboring G245S, R248W, R273C or R273H. Further analysis singled
out one, the Id-1 gene, which produces a protein known to suppress cell
aging and promote tumor aggressiveness. In the third study, Christopher
Evans and his colleagues report development of the first in vivo neuroendocrine
model to study the progression of prostate cancer cells from androgen
dependence to androgen independence. Using the model, the researchers
demonstrated that neuroendocrine differentiation contributes to androgen-independent
prostate cancer growth, proliferation and migration in an androgren-free
environment.
[Top]
Drug
Study Could Boost Prostate Cancer Survivability-(Yahoo News-25/04/2003)
This year in the
United States, nearly 221,000 men will be told they have prostate cancer.
About 30 percent of those cancers will have already spread outside the
prostate. Now, doctors have discovered a way to keep it from spreading
even further. Robert Miller is a force in front of his congregation. Preaching
is his life's work. His life's battle started 11 years ago when he was
diagnosed with prostate cancer. "All I heard was the word cancer and I'm
thinking cancer, death, cancer, death," Miller tells Ivanhoe. PSA levels,
the markers for prostate cancer, are considered high at four. At diagnosis,
Miller's levels were nearly 80. His prostate was removed, but the cancer
stayed behind. He soon found oncologist Michael Carducci, M.D.
When prostate cancer
spreads, it first goes to the bones. Dr. Carducci is studying the drug
atrasentan to keep the cancer from getting there. "This may not necessarily
kill cancer cells per se, it may slow prostate cancer down to a trickle,"
says Dr. Carducci, of the Kimmel Cancer Center at Johns Hopkins University
in Baltimore. It does that by targeting endothelin -- a protein overproduced
in men with prostate cancer that has spread. Dr. Carducci says, "We get
to the lock before endothelin does and therefore, the cancer cells never
see this growth factor, this protein that really stimulates further growth."
Studies show there was a 52-percent delay in the time it took for the
cancer to progress. Miller still has cancer, but it hasn't reached his
bones. He says, "Eleven years ago, I never thought I would see 59. I am
satisfied that God allowed me to live this long."
[Top]
Can
Lifestyle Changes Stop Prostate Cancer?- (HealthScoutNews - 28/04/2003)
Changes in lifestyle
can reverse the progress of prostate cancer, a leading proponent of alternative
medicine says in a claim met with interested skepticism by medical experts.
The claim was made in a presentation Monday by Dr. Dean Ornish, founder
and director of the Preventive Medicine Research Institute in Sausalito,
Calif., at the annual meeting of the American Urological Association in
Chicago. Ornish has been preaching lifestyle change as a way to reverse
heart disease for years, in medical journals and five best-selling books.
His prescription calls for a low-fat vegan diet supplemented with soy
and oxidants, moderate aerobic exercise, stress management and psychosocial
group support. Now he says the same regimen lowered levels of prostate-specific
antigen (PSA), a marker of the cancer, in a one-year study. The study
included 87 men with diagnosed prostate cancer at an early stage, when
doctors often choose to do nothing while they check on the progress of
the tumor -- "watchful waiting," in medical terms.
In the study, 41
of the men were assigned to observe the Ornish regimen carefully, under
supervision. The others were allowed to follow the regimen if they chose,
with no supervision. At the end of three months, PSA levels dropped by
5 percent in the group following the regimen but rose by 1 percent in
the control group, Ornish says. The difference in PSA levels was greater
after one year: down by 3 percent in the regimen group, up 7 percent in
the control group. The regimen must be followed precisely to achieve its
full results, Ornish stresses. Most of the men in the control group tried
to follow the regimen, with middling success; their PSA levels rose --
but not as much as would have happened if they had not adopted some of
the measures, he maintains.
The study's reliance
on PSA levels, however, is seen as a major problem by Andrew Vickers,
an assistant attending research methodologist at Memorial Sloan-Kettering
Cancer Center in New York. "When you get down to it, no one should care
about the PSA level," he says. "It is widely used, but one has to be cautious
in interpreting it. It is a marker of cancer growth, but not necessarily
a one-to-one marker." What Vickers would like to see are measurements
of how the cancer is affecting the patients' quality of life. "The results
they show are highly provocative, but they are not measuring anything
that makes a difference in someone's life," he says. Dr. B. Jay Brooks,
chief of hematology/oncology at the Ochsner Clinic in Baton Rouge, La.,
also looks at the study with a skeptical eye. "This was an extremely small
study, and the endpoint was a rise in PSA, which is not necessarily related
to the progress of the cancer," Brooks says. "The difference between the
experimental group and the control group was extremely small and barely
reached statistical significance." It is "an interesting concept," Brooks
adds, "but this needs to be expanded to a larger group of patients and
followed for a long period of time, perhaps five years." "If it were me
or any of my patients, I would certainly not rely on a change in lifestyle
to affect a proven diagnosis," Brooks sums up.
[Top]
Prostate
Cancer Patients Appear Not to Experience Genetic Damage from Soy Isoflavones-(Cancer.com-21/04/2003)
According to an article
recently published in the American Journal of Clinical Nutrition, soy
isoflavones appear not to damage DNA of cancer patients or healthy volunteers.
The prostate is a male sex gland that is located between the bladder and
the rectum and is responsible for creating a component of semen. Several
treatment options exist for patients with prostate cancer, including watchful
waiting, surgical removal of the prostate (radical prostatectomy), radiation
therapy, cryosurgery, and/or hormone therapy. Researchers are also investigating
complementary and alternative medicine (CAM) therapies. CAM consists of
various therapies, such as acupuncture, massage therapy, and vitamin supplementation.
Clinical research into the efficacy of specific CAM therapies on treating
cancer, managing symptoms, and/or promoting wellness provides evidence
for cancer patients and their physicians seeking to make informed decisions.
Soy is sometimes utilized as a type of CAM and categorized as a biologic/orthomolecular
therapy. Soy comes from soybeans, a plant indigenous to east Asia.
Laboratory research
has isolated components of soy, known as isoflavones, that are believed
to be its active ingredients. Isoflavone is the general name for a class
of compounds that include genistein, daidzein and glycitein. These substances
appear to act as phytoestrogens (plant estrogens), exerting weak estrogen
effects in the body. Several studies have suggested that isoflavones may
help prevent cancer, although clinical trials are needed to confirm these
findings. In addition, soy has been promoted as a potential therapy for
breast and prostate cancer patients. However, in vitro research has indicated
that soy may cause DNA damage to human cells. In the current study, 20
prostate cancer patients received daily doses of 300 mg genistein for
28 days. Over the following 56 days, each patient consumed 600 mg of genistein
each day. At the start of the study, researchers conducted laboratory
tests on peripheral lymphocytes (a type of white blood cell) to determine
baseline DNA damage in each patient. Throughout the study, these tests
were repeated to monitor changes in frequency of broken DNA strands and
rearrangement of genes on DNA.
Six healthy volunteers
also underwent testing. Concurrently, an in vitro study was conducted
to determine the effects of this specific genistein on cultured human
cells. The study reported no changes in the group average or individual
levels of DNA damage. Surprisingly, one test of DNA damage exhibited a
significant decrease within the first 28 days of the trial. As suggested
by previous research, however, genistein did produce genetic damage in
cultured human cells. These researchers concluded that while in vitro
research suggests that genistein can impair DNA, it appears not to induce
such damage in human subjects. Additional research is needed more fully
explore how genistein works in the body and its potential benefits and
drawbacks. These researchers concluded that while in vitro research suggests
that genistein can impair DNA, it appears not to induce such damage in
human subjects. Additional research is needed more fully explore how genistein
works in the body and its potential benefits and drawbacks. Patients with
prostate cancer may wish to speak with their physician about the risks
and benefits of CAM or about participation in a clinical trial further
evaluating CAM therapies such as genistein.
[Top]
DNA
Test May Detect Prostate Cancer Early-(HealthScoutNews-14/04/2003)
Researchers have
created a DNA test that appears to detect the spread of prostate cancer
and also provides early warnings about which men are likely to develop
the disease. Doctors often miss the spread of prostate cancer to other
parts of the body because the migrating cancer cells can be difficult
to detect. The new test could help doctors adjust treatment to fight off
the spreading cancer before it kills the patient, said lead investigator
Donald Malins, principal scientist at the Pacific Northwest Research Institute
in Seattle. Prostate cancer is the most commonly diagnosed cancer among
men in the United States and kills about 30,000 each year, according to
the National Prostate Cancer Coalition. While prostate cancer is easily
treatable in its early stages, many men are not diagnosed until it's too
late.
Malins and colleagues
used a DNA test they developed to examine prostate tissue samples from
49 men, some of whom suffered from prostate cancer. They report their
findings this week in the Proceedings of the National Academy of Sciences.
Forty percent of the samples in healthy men older than 55 showed signs
of damage to the DNA of the prostate. The damage is similar to that in
men who actually have prostate cancer, suggesting that the healthy men
may be in trouble down the line. The information could give doctors a
"heads-up" to "follow the patient closely with the expectation of detecting
and treating cancer at an earlier stage," Malins said. Researchers also
discovered that their DNA test could predict which prostate cancer tumors
would spread to other parts of the body. While prostate cancer cells undergo
changes as they prepare to move beyond the prostate, there's currently
no way to detect the spread other than checking other parts of the body,
Malins said.
The test could allow
doctors to take evasive action against the spread of the cancer, perhaps
by removing the prostate itself to get dangerous tumor cells out of the
body, Malins said. Dr. Durado Brooks, director of prostate and colorectal
cancers at the American Cancer Society, said the DNA test shows promise.
"A tool like this, if it bears out, could be very helpful in really having
a clearer idea about who needs to be either worked up more aggressively
for the possibility of metastasis [spread of cancer] or who needs to be
followed closely," he said. But Brooks added that much more research needs
to be done to confirm that the DNA test actually works. "We're a long
way from having any clinical applications for it," he said. He said that
the DNA test currently requires a biopsy of the prostate cancer. "We're
not going to start biopsying everybody's prostate to see if they're at
risk of prostate cancer," he said. And even if someone is found to be
at risk, there's no guaranteed way to prevent prostate cancer, he added.
Malins said researchers are working on ways to give the DNA tests to patients
in a clinic or even a doctor's office.
[Top]
Dad's
Prostate Cancer Ups Son's Risk of the Disease-(Reuters Health-17/04/2003)
A large research
review confirms that having a father or brother with prostate cancer is
a major risk factor for the disease -- and lends support to regular and
early screening for the cancer in men with a family history, according
to researchers. Their study found that men with an affected first-degree
relative (a father or brother) had a 2.5 times greater risk of prostate
cancer than those without a family history. Having an affected brother
conferred the greatest risk: These men had about a three-fold increase
in cancer risk, while those with affected fathers had about twice the
risk of men with no family history. The findings emphasize that men with
a first-degree relative with prostate cancer should be aware of their
own increased risk, the study authors say. These men "constitute an easily
identifiable high-risk group that could benefit from PSA screening at
an earlier age and at shorter intervals compared with the general male
population," they write in Cancer. Prostate cancer is the second biggest
cancer killer of men in the United States. The American Cancer Society
estimates that 220,000 new cases of prostate cancer will be diagnosed
this year in the U.S., and nearly 30,000 men will die from it. But the
disease's mortality rate is relatively low because it is a slow-growing
cancer, easily cured if caught early.
In the current study,
Maurice P. A. Zeegers, of Maastricht University in The Netherlands, and
colleagues evaluated 33 previously published studies on prostate cancer.
They found that the prostate cancer risk among men with an affected first-degree
family member increased as the number of affected family members rose.
Having just one first-degree family member with the disease more than
doubled a man's risk, while men with two or more affected family members
had a five times higher risk than men with no family history. Having only
a more distant relative affected appeared to raise a man's risk only slightly.
Currently, the American Cancer Society recommends annual PSA testing and
a rectal exam beginning at age 50 -- and at age 45 for African Americans
and men with a family history of the disease, who face a higher risk.
Several other scientific and medical groups do not recommend routine prostate
cancer screening. PSA, or prostate specific antigen, is a protein produced
by the prostate gland. PSA levels above four nanograms per milliliter
(ng/mL) of blood can signal prostate cancer, but not always -- sometimes
a rise in PSA is due to another cause, and sometimes cancer can occur
without a rise in PSA. About 20 percent of aggressive prostate tumors
are found in men with normal PSA levels. Zeegers and his colleagues note
that "ultimately, support for the argument in favor of (prostate cancer)
screening will come from a decrease in ... death rates."
[Top]
Prostate
Cancer Deaths Down; Possible Link To PSA Test-(ET-30/03/2003)
The death rate from
prostate cancer is at an all-time low for both white and black Americans -
and a new study suggests that a primary reason may be increased use of the
PSA blood test (prostate specific antigen test) to find prostate cancer
early. However, study author Kenneth C. Chu, PhD, of the Center to Reduce
Cancer Health Disparities warned men to talk with their doctors about the
pros and cons of being tested. The drop in death rates comes "at the
cost of a very large increase in the number of men treated for prostate
cancer since 1986," wrote Chu and colleagues in the journal Cancer
(Volume 97, Issue 6, 2003: 1507-1516). Treatments can cause serious side
effects and many prostate cancers may grow so slowly they would never
cause health problems if left untreated. The researchers looked at trends
in both newly diagnosed cases of prostate cancer (incidence) and deaths
from prostate cancer (mortality) - then analyzed the trends further by
disease stage. Study data covered from 1969 to 1999 and came in part from
the National Cancer Institute's large national cancer survey program,
Surveillance, Epidemiology, and End Results (SEER), which collects data
from nine population-based US cancer registries.
Prostate cancer
incidence rates rose from 1986 -- when the PSA test was approved --
through 1991, with African-American trends mirroring rates for white men a
year or so later. Then after 1991, death rates for white and black men
began to drop sharply. In 1995, the prostate cancer death rate for white
men age 50-84 years dropped below what it was in 1986, the year the PSA
test was approved. The rate for black men in the same age group passed
that mark in 1997. Death rates continue to decline, which means more men
now survive prostate cancer. "Mortality rates (in 1998-99) are the
lowest since 1950 in white men," said Chu. And among black men, death
rates in 1999 were "the lowest since 1969 when those rates were first
recorded," Chu explained. The record low rate for black men was seen
in men age 50-69 years.
The drop in death
rates for local, regional, and advanced cancers combined was due to fewer
men dying from advanced prostate cancer, according to the new study. But
medical treatments didn't save any more men with advanced cancer --
instead fewer men were diagnosed with advanced ("distant")
disease. Chu and colleagues say the PSA test was finding prostate cancer
in earlier stages, when treatments are more successful. "That is,
tumors that, without intervention, would be diagnosed in the lethal,
distant stage are being detected early by PSA testing, so that men are
diagnosed in the localized or regional stage; the resulting marked
improvement in prognosis leads to decreasing mortality rates," wrote
the study authors. "The PSA test is causing stage shifts from distant
(advanced) disease to more treatable stages of the disease,"
explained Chu.
It's unlikely that
the new report will settle the controversy about whether the PSA test
really helps to save lives. American Cancer Society director of prostate
and colorectal cancer, Durado Brooks, MD, said the report "is not
ground-breaking, but it is important." The findings need to be
confirmed by other studies, and it may be several years before that
happens. Use of the PSA test in other countries has shown mixed results so
far. For example, in the United Kingdom prostate cancer death rates have
dropped recently, as they have in the US. But there has been no large
screening program and there was no large increase in incidence, as seen in
the late 1980s in the US. Until more research provides a definitive answer
about the value of PSA testing, both Brooks and Chu said men should follow
American Cancer Society guidelines on testing for prostate cancer.
Men need to know
the benefits and the limitations of the PSA test and the medical
procedures that may follow, in order to make an informed decision about
whether to be tested. "This does not alter American Cancer Society
recommendations that men talk to their doctors about the advantages and
risks of being screened for prostate cancer," said Brooks. ACS
advises men talk to their doctors beginning at age 50, or at age 45 for
African-American men, and/or earlier if there's a strong family history of
the disease. Chu insists that, "The declines in mortality are big and
they're real." He says credit is due to the American Cancer Society
for the fact that fewer men are dying from prostate cancer…and for
helping more people survive breast and colon cancer as well. "It's a
tribute to the American Cancer Society that their recommendations for
prostate cancer screening, and breast and colon cancer screening, are
causing the declines in mortality rates seen in the 1990s."
Prostate Cancer
Survival Rates 1992-1997 Distant Disease 1 year 3 years Black men 81% 48%
White men 81% 49% Local/Regional 5 years Black men 93% White men 96%
[Top]
Thalidomide
May Slow Some Prostate Cancers: Study-(Reuters Health-27/03/2003)
The drug
thalidomide may slow the progression of prostate cancer in some patients
with advanced forms of the disease, preliminary research suggests. The
small U.K. study of 20 men showed that a low dose of the drug given every
day can reduce levels of prostate-specific antigen (PSA) -- the marker for
the disease -- in just under 40 percent of men with androgen-independent
prostate cancer. Some forms of prostate cancer depend on male hormones
(androgens) to grow, so treatment with androgen-blocking compounds can
stop the development of cancer. But for men with prostate cancer that does
not depend on androgens, such treatment does not prolong survival.
Researcher Dr. Marcus J. Drake, from the University of Newcastle in
Newcastle-upon-Tyne, told Reuters Health the evidence suggests that
thalidomide may extend life by blocking growth factors that stimulate the
development of blood vessels to "feed" tumors. "We are
hoping that for those very high-risk patients, we may be able to
supplement other treatments. By giving them thalidomide, we can reduce
growth factors," he said.
Few drugs in the
history of medicine have aroused as much controversy or fear as
thalidomide. Originally introduced in Britain in 1958 as a sedative, it
was widely prescribed to pregnant women in Europe to treat morning
sickness. But within a couple of years doctors began to hear reports of
terrible deformities in newborns. The drug was withdrawn in 1961. In
recent years, however, thalidomide has emerged as a potential therapy for
a range of diseases including cancers. One of the reasons is that the drug
has powerful anti-angiogenic properties, slowing the development of new
blood vessels that feed tumors.
For the new
research, reported in the British Journal of Cancer, Drake and colleagues
recruited 20 men with progressive cancer who had failed to respond to
hormone therapy. Each was given a daily dose of thalidomide alongside
continued hormone therapy. Out of 16 men who stayed on the drug for at
least two months, six experienced a drop in PSA levels of around 48
percent, with three of them seeing a decline of 50 percent or more.
However, patients did have side effects such as constipation, headache,
nausea and weight gain. The researchers conclude that thalidomide may be a
useful treatment for some patients but needs close monitoring. "The
current results indicate low-dose thalidomide can decrease PSA levels in
just under 40 percent of patients with androgen-independent prostate
adenocarcinoma, suggesting the potential for improved disease
control," they write.
[Top]
Age
Not a Factor in Prostate Cancer Survival (HealthScoutNews-19/03/2003)
Younger people with
prostate cancer don't necessarily have a poorer chance of survival than
older people. That's the good news from a study in the current issue of
the International Journal of Radiation Oncology, Biology and Physics. The
traditional view is that younger people diagnosed with prostrate cancer
earlier have more aggressive tumors. Dr. Peter A.S. Johnstone, of the
Naval Medical Center in San Diego, and his colleagues analyzed records
from the Department of Defense Center for Prostate Disease Research to
determine disease-free survival rates of prostate cancer patients who had
radiation therapy. They examined the records of 1,018 people who had T1-T3
prostate cancer and were treated with radiation therapy between 1988 and
2000. The median follow-up was 85.3 months as of Dec. 31, 2001. The study
found that age didn't have a significant effect on disease-free survival.
"Along with the bias that younger patients are more at risk, there is
also a perception that younger patients are better suited to surgery than
radiation therapy," Johnstone says in a news release. "While our
results did not allow us to draw any conclusions about the effectiveness
of radiation versus surgery, this study questions the view that age should
have any influence on the selection of treatment modality,"
[Top]
Prostate
Now the Leading Cause of UK Male Cancer-(Reuters-23/03/2003)
Prostate cancer is
now the leading cause of cancer in men in Britain, ahead of lung cancer
for the first time, according to new figures. The Prostate Cancer Charity
said the latest available figures showed that 23,369 men were diagnosed
with lung cancer in 1999, against 24,908 with prostate. Britain's largest
cancer organization, Cancer Research UK, confirmed that prostate was now
the commonest male cancer. Chris Hiley, head of policy and research at the
Prostate Cancer Charity, told Reuters several factors were responsible.
Male lung cancer rates were falling because fewer men smoked while the
aging of the population and greater use of diagnostic tests meant prostate
cancers was on the rise.
The charity is
campaigning to raise awareness of the disease and is funding research to
develop a more reliable diagnostic test than the existing blood test.
Though widely used in the United States, so-called PSA testing is not
recommended for general screening in the UK because it gives so many false
positive results and because physicians are unsure how to treat early
disease. Unlike lung cancer, which remains a major killer, prostate cancer
is often less aggressive. Many elderly men with the disease die from other
causes, unaware they ever had prostate cancer. Even so, the disease kills
around 10,000 men in Britain every year.
[Top]
High
Calorie Intake Tied to Prostate Cancer Risk-(Reuters Health-06/03/2003)
Men who take in
lots of calories, regardless of what foods they eat or their body weight,
may be more likely to develop prostate cancer, study findings suggest.
Among 444 middle-aged and older men, those who reported the biggest
calorie intake had a nearly four-fold higher chance of being diagnosed
with prostate cancer, versus men who consumed the fewest calories. The
results are based on a fairly small number of men with the disease; 46 had
been diagnosed with prostate cancer before reporting their dietary habits,
while 22 were diagnosed after.
Still, researchers
report in the journal Urology, the findings support the theory that a
high-calorie lifestyle is associated with higher odds of prostate cancer.
The role of diet in prostate cancer has long been unclear. A number of
studies have suggested that diets high in animal fat, from meat or dairy
products, may help promote the disease. But other research has found no
such connection. In this study, total calories from any source--fat,
protein or carbohydrates--were what mattered. The group with the highest
calorie intake--typically around 2,600 calories a day--had a higher cancer
risk than any of the lower-intake groups. Compared with men who reported
the lowest calorie intake (half of them getting less than 1,100 calories
per day), their risk was 3.8 times higher.
The association was
true of both normal-weight and overweight men, according to the
researchers, led by Lillian J. Hsieh of Johns Hopkins University in
Baltimore, Maryland. When they looked only at men who were diagnosed after
reporting their diet habits, though, the relationship between calories and
prostate cancer was less strong. According to Hsieh and her colleagues,
higher calorie intake may influence prostate cancer development by
increasing a man's levels of certain hormones. For example, they note,
levels of circulating insulin-like growth factor-1 have been associated
with prostate cancer.
Another recent
study found a similar relationship between higher total calorie intake and
prostate cancer. But those researchers also discovered a link between a
high-fat, high-calcium diet and the risk of advanced prostate cancer, in
particular. They speculated that taking in lots of calories might boost
prostate cancer risk overall, while fat- and calcium-rich diets might
promote the advancement of the disease. It's estimated that about half of
US men will develop some cancerous cells in the prostate by the age of 80.
But far fewer die from prostate cancer, since it is usually a slowly
progressing disease. Risk factors include older age, family history of the
disease and African-American race. According to Hsieh's team, more studies
that measure men's calorie intake, physical activity and weight over time
are needed to understand the role of diet in the disease.
[Top]
Green
Tea Doesn't Treat Advanced Prostate Cancer-(Reuters Health-04/03/2003)
Despite previous
research touting the promise of green tea for prostate cancer treatment, a
new study shows it does little to help men with advanced disease. Among 42
men with advanced prostate cancer who ingested highly concentrated forms
of green tea, only one showed fleeting signs of improvement. And the
majority of patients developed side effects such as nausea, vomiting,
insomnia and confusion, which the study authors suggested may stem from
the caffeine contained in green tea. Green tea "didn't work,"
study author Dr. Aminah Jatoi of the Mayo Clinic in Rochester, Minnesota
told Reuters Health. But she cautioned that these results only apply to
men with advanced prostate cancer that has become resistant to hormonal
therapies.
The current study
should not discourage investigators from studying the benefits of green
tea for other forms of the disease, she noted. "I wouldn't want
anybody to think that just because it didn't work in this setting, there
are not other possibilities for testing it in the future," Jatoi
said. Researchers became inspired to study green tea's effects in humans
after laboratory experiments and investigations in animals suggested the
drink could suppress prostate cancer. Green tea contains substances known
as polyphenols, which laboratory research has shown can suppress the
growth of tumors and destroy prostate cancer cells that do not respond to
hormones, generally considered an advanced form of the disease. Previous
research has also shown that green tea treats prostate cancer in mice, and
that the disease is slightly less likely to appear among men who regularly
consume green tea.
During the current
study, published in the journal Cancer, Jatoi and her colleagues at the
Mayo Clinic and the North Central Cancer Treatment Group asked 42 men with
advanced disease to drink six concentrated doses of green tea every day.
Jatoi estimated that this amount was roughly equivalent to between six and
12 daily glasses of store-bought green tea. Each month, doctors checked
patients' blood for levels of a protein called prostate specific antigen (PSA),
which is over-produced by cancerous prostate cells. In general, a rise in
PSA is considered an indication that prostate cancer is progressing, and
not responding well to treatment. During the study, only one patient had
at least a 50% decrease in his blood levels of PSA, an improvement that
only lasted two months. At the end of one month of treatment, half of the
men included in this study had experienced an increase in their PSA levels
of at least 43%. Almost seven out of 10 men also reported side effects
from the treatment, a number of which were potentially serious. Jatoi
explained in an interview that she did not believe that the disease
worsened as a result of green tea, for all patients in the current study
had advanced forms of prostate cancer, which, without effective treatment,
can progress quickly in the body. "I think what we were seeing was
the natural history of the disease," Jatoi said.
[Top]
Tall
Men at Higher Risk of Prostate Cancer-(HealthScoutNews-19/02/03)
Older men who are
tall have a higher risk of getting prostate cancer, a new Harvard study
suggests. "These are modestly increased risks," says study author Dr.
J. Michael Gaziano, chief of the division on aging at Brigham and Women's
Hospital, an affiliate of Harvard Medical School in Boston. Using data
from the Physicians Health study of 22,071 men in the United States, the
researchers zeroed in on 1,634 men with prostate cancer, asking about
their age, height, weight and body mass index (BMI), a ratio of height
to weight.
They evaluated three
categories of height: less than 5 feet 10 inches; 5-foot-10 to 5-foot-11;
and over 5-foot-11. Among the men who were 50 to 59 years old, those 5-foot-10
to 5-foot-11 had a 21 percent greater risk of prostate cancer than those
under 5-foot-10. Those over 5-foot-11 had a 32 percent greater risk. For
men who were 60 to 84, those who were 5-foot-10 to 5-foot-11 had a 22
percent higher risk than shorter men in the same age bracket, while those
above 5-foot-11 had a 24 percent higher risk. . Exactly why is not known,
Gaziano says: "We've seen an association with shorter people having an
increased risk for cardiovascular events, and we don't know why [that
happens] either." "Height might just be a genetic marker for some other
genetic reason you might be at risk," he speculates.
The study is not
the first to link taller height with prostate cancer, Gaziano says. Other
researchers have studied the association, with mixed findings. "The data
in general [on the topic] are very limited, and this needs to be explored
and then duplicated or refuted before we can say something definite,"
he says. The researchers did not find an association between weight or
BMI with prostate cancer.
This year, about
220,900 new cases of prostate cancer will be diagnosed in the United States,
according to the American Cancer Society. Early prostate cancer usually
has no symptoms; risk factors include increasing age, ethnicity and family
history. More than 70 percent of all prostate cancers are found in men
who are over age 65. Black men have the highest prostate cancer rates
in the world. An annual digital rectal exam and a PSA blood test to detect
levels of prostate specific antigen are recommended by the American Cancer
Society for all men beginning at age 50; for those at elevated risk, the
recommended age for the tests is 45.
Another expert, Dr.
Allan Pantuck, notes previous studies have yielded conflicting findings
about prostate cancer risk and height, weight and BMI. "Most show an association
with obesity," he says. Also, the latest study is an observational one
and does not prove a cause-and-effect relationship, adds Pantuck, who
is an assistant professor of urology at the University of California,
Los Angeles, Jonsson Cancer Center. What's the take-home point for tall
guys? "Obviously men can't change their height, and we already know men
over age 50 are the group for whom we recommend prostate cancer screening,"
Pantuck says. Gaziano agrees, but stresses that men should continue to
observe the recommendations for screening. Eventually, if more research
bears out the association between height and prostate cancer, it will
help researchers and physicians better zero in on the men most likely
to contract the disease, he says. Dr. Noriko Kojimahara of Japan, who
conducted the research while at Harvard, will present the study's findings
at the American College of Preventive Medicine meeting in San Diego.
[Top]
Soy-Tea
Combo May Thwart Prostate Cancer-(HealthScoutNews-05/02/03)
The same two foods
that many scientists believe reduce the risk of breast cancer in women
may also protect men from prostate cancer. That's the conclusion of a
new Harvard University study that looked at the power of tea and soy to
inhibit the growth of prostate tumors in mice. Unlike other studies that
examined the food's individual effects on tumor growth, the new research
focused on the power that came from the combined effect of tea and soy
together. "I think the most important finding is that consumption of both
soy and tea has a synergistic effect," says study author Jin-Rong Zhou,
adding that each appears to reinforce the power of the other to fight
cancer.
The study appears
in the Journal of Nutrition. Zhou says he got the idea to test the soy-tea
combination when statistical data showed that China had one of the lowest
prostate cancer risk profiles in the world. Sensing that diet may play
a key role, he dissected Chinese food habits and looked at what the men
were eating most. While a number of foods made the list, Zhou says tea
and soy jumped out, mostly because previous studies showed they may possess
anti-cancer properties. "By combining the facts that soy and tea are more
commonly consumed [in China] and their bioactive components are more potent
than other dietary components, we proposed that they are effective dietary
components, especially in combination, for prostate cancer prevention,"
Zhou says.
Zhou and his colleagues
put their theory to the test on 16 mice, each genetically engineered to
grow tumors in the prostate region. All the mice ate a diet of protein,
carbohydrates, vitamins and minerals, while some were also fed daily doses
of soy compound in varying amounts. Infusions of both black and green
tea were given to all the mice to drink. The amount of soy consumed by
the mice would be equivalent to about 250 milligrams per day for a human,
while the tea dose was equivalent to about 6 to 8 cups a day, Zhou says.
At the end of the study, the mice were examined for not only the presence
of prostate tumors, but also the size of the tumors, their rate of growth
and how much the disease had spread. These figures were then analyzed
in regard to soy and tea consumption.
What the researchers
found: Individually, the soy complex, and the black and green tea reduced
the rate at which tumors developed. When tumors did grow, they were smaller
when either tea or soy was consumed. However, when taken together, the
tea-soy combination was even more powerful, not only at inhibiting tumor
growth, but also at reducing the weight of any tumors that did develop,
as well as controlling the spread of cancer to nearby lymph nodes. The
soy and green tea combination also reduced hormone concentrations linked
to prostate cancer. Ultimately, both tea-soy combinations inhibited angiogenesis,
a process in which tumors grow blood vessels to stay alive.
The bottom line:
Alone and especially together, tea and soy exhibited powerful anti-prostate
cancer effects, the study says. For nutritionist Jyni Holland, the research
holds promise, but she doesn't think men should flood their diet with
tea or soy just yet. "Keep in mind that it was a mouse study, and many
promising animal results never translate to human success," says Holland,
a clinical nutritionist at New York University Medical Center. At the
same time, she says that since both tea and soy have been shown in other
studies to yield many important health benefits, adding them to your diet
in moderation could have positive results. "I wouldn't run out and buy
soy or green tea supplements. But if you want to include these foods in
your diet, then you may be well ahead of the game if and when this research
does prove true in humans," Holland says.
[Top]
Herbal
Treatment Shows Promise Against Prostate Cancer- (HealthScoutNews-20/12/2002)
An
herbal formula sold under the brand name Zyflamend may offer new treatment
and prevention options for prostate cancer patients, say Columbia University
researchers. The formula, a combination of 10 different herbs, suppressed
the growth of prostate cancer cells and caused many cells to self-destruct
in lab experiments, report the researchers. They presented their findings
at a recent meeting of the Society of Urologic Oncology at the National
Institutes of Health in Bethesda, Md. "This is a natural product that
contains herbs and spices and in our lab studies seems to have an effect
on the cancer we looked at," says one of the study's authors, Dr. Aaron
Katz, director of the Center for Holistic Urology at Columbia-Presbyterian
Medical Center in New York City. "The compound needs future research on
the clinical side, but it holds the potential for prevention and reducing
PSA (prostate-specific antigen) levels."
Prostate cancer is
the most common cancer in men, except for skin cancer. More than 189,000
men are diagnosed with this form of cancer every year, according to the
American Cancer Society. Zyflamend is made with a combination of turmeric,
ginger, holy basil, hu zhang, Chinese goldthread, barberry, oregano, rosemary,
green tea and Scutellaria baicalensis. The researchers added Zyflamend
to prostate cancer cells in lab cultures. They also tested the effects
of curcumin, a compound from the spice turmeric. Curcumin is believed
to have an anti-inflammatory effect that could reduce the growth of prostate
cancer. They found Zyflamend reduced the growth of prostate cancer cells
and induced cell death, and that curcumin alone did not produce these
effects.
Dr. Howard Korman,
a urologist and prostate cancer specialist at William Beaumont Hospital
in Royal Oak, Mich., says the results of this new study are exciting.
"Some of our most effective medicines come from plants," says Korman,
"and these results are interesting and hopeful." However, he cautions,
"it's a big step to go from the lab to people." Katz says the researchers
are hopeful the therapy will be as effective in people as it is in the
lab, and they plan on conducting clinical trials in the future. If it
proves as effective as they hope, Katz says the herbal formula could be
used as preventative therapy because it has no significant side effects.
He says it could also, perhaps, be used as a treatment for men with small
tumors who don't want to undergo surgery or radiation if the trials go
well.
[Top]
Value
of Prostate Cancer Screening Unclear: Panel- (Reuters-03/12/2002)
Screening for prostate
cancer provides only uncertain benefits, a US government panel found,
saying there was not enough evidence to recommend for or against men undergoing
routine tests. The report's findings, based on a review of studies of
the effect of screening for the disease, the second-leading cancer killer
of US men after lung cancer, add to a growing debate on the subject. "While
the jury is still out on the value of routine screening to improve health
outcomes, patients should talk with their clinicians to make individualized
decisions," Alfred Berg, head of the panel and chair of the University
of Washington's Department of Family Medicine, said in a statement. "Men
will need to make this decision based on their personal preferences and
values until we have better scientific evidence on whether screening is
effective."
Some 189,000 men
will be affected by prostate cancer in 2002 and 30,200 will die from it,
according to the American Cancer Society. But the latest report, by an
independent task force sponsored by the Agency for Healthcare Research
and Quality, echoes the findings of other researchers in October that
questioned whether the benefit of screening outweighed its harms. Men
older than 50 are often advised to get a blood test that checks for the
cancer by measuring the level of prostate specific antigen (PSA), a protein
produced by prostate cells and especially by prostate cancer cells. The
PSA test and another procedure called a digital rectal exam have both
been found to be effective at catching the cancer. But prostate cancer
can be a slow-growing disease, and many men are found to have had the
disease after they die of something else--often heart disease, the No.
1 killer of both men and women in the industrialized world.
Men who are diagnosed
with prostate cancer and do decide on treatment may undergo surgery or
radiation therapy that can leave them impotent, incontinent or with bowel
dysfunction. Researchers are increasingly questioning whether it is worth
having patients go through such ordeals given that most patients are older
than 65 and many are likely to die from something else while living with
the cancer. The task force, which recommended against prostate cancer
screening in 1996, said other studies currently under way and due to present
their conclusions over the course of the decade would shed more light
on the issue. In the meantime, it noted that men older than 45 who have
prostate cancer risk factors, such as African-American heritage or an
immediate family member with the disease, as well as men ages 50 to 70
with an average risk, were most likely to reap any benefits from screening.
"Older men and men with other significant medical problems who have a
life expectancy of fewer than 10 years are unlikely to benefit from screening,"
the report said.
[Top]
Study:
Some Herbal Meds Interfere with Cancer Drug-(Reuters Health-05/11/2002)
An herbal dietary
supplement that some men use to treat prostate cancer may interfere with
the anti-cancer activity of the chemotherapy drug paclitaxel, making it
less effective, researchers report. The supplement, PC-SPES, includes
extracts from eight different herbs, and consequently, hundreds of different
compounds. "If a patient were taking PC-SPES concurrently with paclitaxel,
the paclitaxel may have less anti-tumor effect," study author Dr. Peter
S. Nelson of the Fred Hutchinson Cancer Research Center in Seattle, Washington
said. He and his colleagues compared the effects of the herbal remedy
and the prescription drug in laboratory and mouse studies and found that
both PC-SPES and paclitaxel reduced the size of cancer tumors. Their findings
are published in the Journal of the National Cancer Institute.
Paclitaxel, however,
had the greatest anti-tumor effect, the report indicates. Tumor size was
also reduced when the two medicines were combined; however, the result
was comparable to those seen when paclitaxel was used independently. In
fact, the herbal therapy seemed to make paclitaxel less effective. PC-SPES
appears to hinder the growth of cancer cells by inhibiting the assembly
of certain cell structures called microtubules. "We believe there is a
chemical or compound within this complex mixture that has this activity,"
Nelson said. However, paclitaxel works by doing the opposite: inhibiting
the disassembly of these same microtubular structures. "Our results suggest
that PC-SPES and paclitaxel may have conflicting effects if administered
together in the clinical setting. The studies reported here provide a
cautionary note emphasizing the potential hazards of combining complex
poorly defined botanical compounds with conventional medical therapies,"
they add.
Men with prostate
cancer who use PC-SPES or any other herbal or complementary medicine should
therefore inform their doctors of such use, Nelson said. "Most (complementary
medicines) will likely have no or minimal interactions with known drugs;
others may have significant interactions."
[Top]
Study:
Garlic May Prevent Cancer-(AP-06/11/2002)
Men in China have
the lowest rate of prostate cancer in the world, and a diet rich in garlic,
shallots and onions may be one of the reasons. Researchers at the National
Cancer Institute report in a new study that a diet with lots of vegetables
from the allium food group - which includes garlic, shallots and onions
- reduces the risk of prostate cancer by about half. And the common Chinese
diet includes hearty servings of these vegetables. Men who are interested
in preventing prostate cancer should make sure that their diet includes
plenty of garlic, scallions, chives and other vegetables in the allium
family.Previous
research has also linked the intake of allium vegetables to a lower risk
of stomach, colon and esophagus cancer. These vegetables are rich in the
antioxidants known as flavonols and other compounds that have been found
to inhibit tumor growth in laboratory studies.
The study, appearing
in the Journal of the National Cancer Institute, is based on interviews
with 238 men with prostate cancer and 471 men who were free of the disease.
Men in the study, all residents of Shanghai, China, were asked how frequently
they ate 122 food items. The results showed that those who ate more than
a third of an ounce a day from the allium food group were about 50 percent
less likely to have prostate cancer than those who ate less of the foods.
"We checked on many food items and the allium food group stood out (as
protective against prostate cancer)," said Ann W. Hsing, an NCI epidemiologist
and the first author of the study. "But the conclusions need to be replicated
in another study." She said the study was conducted in Shanghai because
China has the lowest rate of prostate cancer in the world.
Scallions seemed
to be the most protective. According to the study, men who ate about a
tenth of an ounce or more a day of scallions reduced their prostate cancer
risk by about 70 percent. For garlic consumption of the same amount, the
prostate cancer risk was reduced by about 53 percent. Hsing said that
the typical Chinese diet is much more heavily seasoned with garlic, scallions
and onions than is the traditional American diet. But even so, the amount
of allium vegetables consumed is measured only in fractional ounces. For
instance, the study suggests that an effective level of prostate cancer
protection can be achieved with about one clove of garlic a day. "The
reduced risk of prostate cancer associated with allium vegetables was
independent of body size, intake of other foods and total calorie intake,"
the study authors reported. Hsing said the study reinforces earlier studies
that have linked high vegetable consumption to a reduced risk of prostate
cancer.
For instance, earlier
studies have found that that eating tomatoes and tomato products can lower
risk of prostate cancer. Italy, where tomato sauce and garlic are favorites,
has one of the lowest rates of prostate cancer in Europe, said Hsing.
Janet Stanford, a cancer epidemiologist at the Fred Hutchinson Cancer
Research Center in Seattle, said the study by Hsing and her co-authors
continues to support the general finding that "eating vegetables is a
good thing." Stanford said her group, in an earlier study, linked broccoli,
cauliflower and related vegetables to a reduced prostate cancer risk,
while a high fat diet increased the risk. "This shows that your mother
was right," said Stanford. "Eat more vegetables."
[Top]
Prostate
Cancer Drugs May Spur Tumors-(HealthScoutNews-07/11/02)
A family of drugs
that men with advanced prostate cancer take to suppress their disease
may, after time, promote cancer cell production. The medications are called
anti-androgens, say researchers at the University of Rochester. The discovery
of this unwelcome side effect is of more value to scientists than to prostate
cancer patients, at least for now. The reason: Anti-androgens are currently
one of the most effective treatments for men with advanced prostate cancer,
says University of Rochester urologist Dr. Edward Messing. "It is a big
finding from a biological point of view, but from a clinical point of
view, while it could be potentially beneficial, more work has to be done,"
Messing says.
The standard treatment
for men with advanced prostate cancer -- defined as the spread of the
cancer beyond the prostate gland -- is to take anti-androgens. These drugs
block the production of the male hormone testosterone, which prostate
cancer cells need to grow. Without the hormone, the cancer cells die,
the researchers say. Doctors have long known that for some reason, the
cancer-suppressing effect of anti-androgens stops after a period of time,
usually between 18 to 24 months. The patients' cancer then reappears.
The researchers at the University of Rochester's George Whipple Laboratory
for Cancer Research have found that anti-androgens, while suppressing
testosterone production, also activate a molecule known to cause cancerous
cells to grow. "We never thought this drug had a second role," says Chawnshang
Chang, a urology professor who headed the research. "It suppresses the
androgen, but also activates a molecule known as MAP kinase that has been
linked to tumor growth."
Chang says the anti-androgen
drugs, like hydroxyflutamide, successfully block testosterone production
by suppressing the protein that acts as an androgen receptor. But the
researchers found that, after time, as testosterone production declines,
MAP kinase activation becomes more pronounced. "We don't know the mechanism
for this," he says. "We know the outcome, but not the mechanism." The
Rochester researchers' finding, which earned an award for outstanding
research from the American Urological Association, is described in Cancer
Research.
There are about
2.8 million cases of prostate cancer diagnosed annually in the United
States, and 30,000 deaths a year from the disease, according to National
Vital Statistics reports. There has been intensive research into the causes
of and potential cures for the disease. Chang has long been interested
in discovering why the anti-androgens eventually lose their power to combat
the cancer. He and his colleagues studied cancer cells from four men with
advanced prostate cancer, comparing cells from early in their disease
to cells after the anti-androgen therapy became ineffective. They found
that the levels of the molecule MAP kinase were much higher in the cells
of the men after they had had the hormone therapy. "Before taking the
drug, the levels were really low. Afterwards the levels were really high,"
Chang says.
Messing, who worked
with Chang on the findings, says, they "found that cells that had no androgen
in them at all were still replicating. The hydroxyflutamides can turn
on signals that eventually make the cells divide in the absence of the
androgen receptor." Chang says the finding should spur drug companies
to create new types of anti-androgen drugs that don't activate the MAP
kinase molecule, or to perhaps combine the existing anti-androgen drugs
with another drug that might suppress the MAP kinase molecule.But
for now, he says, "There is no good drug available."
Dr. Edward Gelmann,
professor of oncology at the Georgetown University Medical Center's Lombardi
Cancer Center, says there are experimental drugs that could be used to
thwart the MAP kinase molecule. "There are no [such medicines] in clinical
trials, but there are experimental medicines," he says. In the meantime,
Messing says, the new findings should prod doctors to carefully monitor
their prostate cancer patients to determine when the anti-androgen drugs
may no longer be suppressing androgen, but activating the MAP kinase molecule.
A good measure is a blood test called the PSA count, which gauges levels
of prostate specific antigen. "When the PSA goes up, don't wait to stop
the drug," Messing says. This is already the clinical strategy, Gelmann
says. "We do that anyway."
[Top]
Breast
Gene Fault Increases Prostate Cancer Risk-(Reuters-30/10/2002)
A genetic fault
that makes women more susceptible to breast and ovarian cancer also raises
a man's risk of developing prostate cancer, a British scientist said.
Dr. Ros Eeles, a medical geneticist at The Institute of Cancer Research
in southern England, told a medical conference that men with an inherited
defect in the BRCA 2 gene have a five-to-seven fold increased risk of
prostate cancer than those without the fault. She announced plans to launch
a European-wide study of 500 men who have four or more close relatives
who have developed breast cancer before the age of 60. They may have inherited
the mutation and would be more likely to develop prostate cancer. "We
are trying to see if you can identify a high-risk group (of men) that
you can target for screening," Eeles told the first annual meeting of
the medical charity Cancer Research UK.
Forty percent of
early onset, aggressive prostate cancers are linked to inherited factors.
Some are due to alterations in the BRCA 2 gene, according to Eeles. The
trial, which is due to begin in December or January, will be among the
first to use genetic screening to target men in this way. "The crucial
thing about screening for prostate cancer is to identify those men with
a high risk of an aggressive form of the disease," Eeles added.
Prostate cancer is
a leading cause of cancer deaths in men. In the United States alone this
year about 200,000 men will develop the disease and 40,000 will die from
it. The prostate specific antigen, or PSA test, helps doctors detect early
signs of the disease but scientists have questioned its accuracy. The
test is also not very good at indicating whether it is a quick or slow-growing
cancer. "At the moment it is the best test we've got," said Eeles. The
disease is more common in older men. Very few men under 50 years old suffer
from it. Half of all cases are in men aged 75 and over. It is normally
treated with surgery or radiation. The BRCA 2 gene mends damage to DNA.
Mutations in the BRCA 1 and BRCA 2 genes increase breast cancer risk.
Eeles and her colleagues will screen the men with the BRCA2 mutation with
the PSA test for five years and offer biopsies to men with raised levels
of the antigen. They will compare the number of men who develop the illness
with results from a randomized PSA trial of men being done in the Netherlands.
"As scientists' understanding of cancer genetics improves, pressure on
screening programs will increase dramatically and it will not be possible
to screen every man -- we need a more targeted approach," Eeles added.
[Top]
Gene
Predicts Prostate Cancer's Virulence (HealthScoutNews-10/10/2002)
A
gene that silences tumor-blocking proteins is a red flag for aggressive
prostate cancer, new research says, and men having low levels of it could
be spared unnecessary treatments. The gene, EZH2, is much more active
in aggressive prostate tumor cells than in either localized cancer or
in healthy prostate tissue. "This helps us distinguish between aggressive
prostate cancer and slow-growing prostate cancer, and allows us to identify
patients appropriate for watchful waiting and those who need radical [prostate
removal surgery] or radiation," says Dr. Arul M. Chinnaiyan, a University
of Michigan pathologist and leader of the research effort. The study appears
as a research letter in Nature.
Prostate cancer affects
roughly 190,000 American men a year, killing 30,000. Metastatic prostate
tumors are almost always lethal. EZH2 belongs to a family of genes called
transcription repressors, which prevent cells from copying and carrying
out the instructions of other genes. It also belongs to a cluster of genes
that help cells remember their specific function as they divide. When
Chinnaiyan's group boosted EZH2 protein levels in prostate cells in a
dish, they saw that the activity of 163 other genes flagged -- yet no
other genes revved up. Some of these genes that were shut down can help
cells fight cancerous mutations. In another experiment, when they disabled
EZH2 with small bits of genetic material called RNA, cell division halted.
"Not only is EZH2 likely involved in proliferation and progression, but
it could serve as a therapeutic target, too," Chinnaiyan says. However,
he adds, the researchers have yet to test that approach in lab animals
or patients.
EZH2 is also present
in certain forms of blood cancers such as lymphoma, though its utility
as a marker for these diseases isn't clear. Bruce Zetter, a cancer biologist
at Children's Hospital in Boston who studies why tumors become metastatic,
says EZH2 seems to behave like the first in a line of dominoes: Tipping
it sends the whole array into a tumble. Knowing which genes encourage
the spread of cancer is valuable for all tumor types, but especially for
prostate cancer, Zetter says, since the disease isn't deadly for most
men. "What we need in prostate cancer is a better prognostic marker. We
don't need to improve the diagnosis so much," says Zetter, co-author of
a commentary on the study. "That's what these latest developments are
paving the way to do. "Doctors
currently have little success at eradicating large tumors that have migrated
from a main site, Zetter says. But in the future, thanks to early detection
of smaller metastases, they will be able to use therapies like tumor vaccines
and low doses of anti-cancer drugs to suppress these wanderers before
they become deadly.
In earlier work,
Chinnaiyan and his colleagues discovered a gene called AMACR, which could
help solidify a diagnosis of prostate cancer in the event of a fuzzy biopsy.
Such ambiguity occurs in about 15 percent to 20 percent of samples. AMACR
might also improve screening for prostate cancer, which is now done by
a test for prostate-specific antigen, or PSA. This test picks up elevations
in a blood protein shed by prostate tumors. Unfortunately, it's produced
by benignly enlarged glands, too, leading to much unnecessary treatment.
AMACR, on the other hand, appears only to be elevated in the presence
of cancer, so a positive result would signal a tumor. Chinnaiyan is now
working on combining AMACR and EZH2 into a single genetic test that would
both identify the presence of prostate cancer and determine its virulence.
The cost of such a test would not be exorbitant, he adds.
[Top]
Prostate
Cancer Patients Back Screening Program (Reuters-04/10/2002)
Men suffering from
prostate cancer support screening programs to detect early signs of the
disease, although the jury is still out on whether testing saves lives,
doctors said. Medical experts are debating the evidence on the prostate
specific antigen or PSA test, which measures levels of a molecule that
is overproduced by cancerous prostate cells. PSA testing can detect the
disease before symptoms occur. But research has shown that men may be
getting unnecessary treatment because they would have died of something
else, and there is conflicting evidence about whether testing reduces
deaths from the disease. But most British men with the illness say they
would recommend it for their friends and sons and believe a national screening
program would encourage men to be tested.
"Doctors, policy
makers and politicians need to understand why people want wider access
to PSA testing, so that they can find better ways of communicating information
about the risk," Alison Chapple of Oxford University in England said in
a report published in The British Medical Journal. British health officials
are considering the merits of a free national screening program. Currently
patients in the UK have to request a test specially or obtain one through
private health care. Chapple and her colleagues interviewed men with confirmed
or suspected cases of the illness. Nearly all of them said screening should
be more widely available because symptoms of the disease can be ambiguous.
Greater access would also encourage more men to get tested.
In a separate study
in the journal, scientists at Harvard Medical School in the United States,
where the test is widely available, compared its impact on prostate cancer
death rates in two areas of the country. Between 1987-1990, men in the
Seattle area of Washington state were five times more likely to have the
PSA test than men in Connecticut where it was adopted more slowly. The
men living in Washington also had higher rates of surgery and radiotherapy
to treat the illness, but after an 11-year follow-up the scientists said
the death rates from the disease in the two areas were similar. Harvard
professor Michael Barry and his colleagues said a longer follow-up of
the patients was needed, as well as more research. "Ongoing randomized
trials assessing the effectiveness of screening and treatment for prostate
cancer should be supported," he said in the report.
[Top]
Heart
Disease Gene Also Linked to Prostate Cancer (Reuters Health-16/09/2002)
A gene already associated
with heart disease may also play a role in prostate cancer, new study
findings suggest. Mutations in the macrophage scavenger receptor-1 (MSR-1)
gene were found in 4.4% of white men with prostate cancer, compared with
0.8% of men without the disease. Gene mutations were found in 12.5% of
black prostate cancer patients compared with 1.82% of black men without
prostate cancer. The men had different mutations of the gene, some of
which were linked with an aggressive form of cancer, according to the
report in the online version of the journal Nature Genetics.
"One of the mutations
leads to prostate cancer that has rapid metastasis (spread)," Dr. Jianfeng
Xu, of the Wake Forest University School of Medicine in Winston-Salem,
North Carolina, who led the research, said in a statement. Working with
a team at Johns Hopkins University in Baltimore, Maryland, Xu and a large
group of colleagues looked at the DNA of 159 men with hereditary prostate
cancer and their families. They found that 13 families, or 8% of those
with hereditary cancer, had MSR-1 mutations. Different families had different
mutations in the gene, the researchers said. In a second analysis, the
researchers screened 365 men with non-hereditary prostate cancer and compared
them to more than 366 men without prostate cancer. They found that 4.4%
of white men and 12.5% of black men with non-hereditary prostate cancer
had mutations in the gene.
Just as there are
a number of gene mutations associated with the inherited risk of breast
cancer, there are likely to be several genes involved in prostate cancer,
the researchers said. But, they added, MSR1 appears to be the strongest
gene linked to inherited prostate cancer risk yet found. The MSR1 gene
is active in white blood cells known as macrophages, which attack and
"eat" bacteria or diseased cells. The gene was found more than 20 years
ago to play a role in the accumulation of fatty plaque in arteries, a
characteristic of heart disease. Mice bred to lack the gene are unable
to fight off certain infections. The Johns Hopkins team has done work
that suggests people with some versions of the gene do not fight certain
infections as well as others.
This may help explain
one theory that associates prostate cancer with certain infections. Inflammation--the
body's response to infection--is also associated with hardening of the
arteries and heart disease. "In summary, we have presented genetic evidence
showing that MSR-1 may have an important role in susceptibility to prostate
cancer," write Xu and colleagues. "Given the modest amount of evidence,
however, follow-up studies are necessary to verify the associations observed
in this study," the team concludes. Prostate cancer is the most common
cancer in men, after lung cancer. The American Cancer Society says 189,000
men will be diagnosed with prostate cancer this year in the United States
and 30,000 will die of it.
[Top]
Early
Surgery Shown to Cut Prostate Cancer Deaths (Reuters Health-11/09/02)
In findings expected
to help answer the long-debated question of how to treat early prostate
cancer, new research shows that prostate removal does cut men's risk of
dying from the disease. What's more, researchers say, although such surgery
often carries significant side effects including impotence and incontinence,
patients' overall quality of life after surgery may be no different from
that of men who opt for "watchful waiting." The question of whether to
aggressively treat early prostate cancer is controversial, due to both
the nature of the disease and the risks of treatment.
It is estimated that
by the time they reach age 75, at least half of men have some cancerous
changes in their prostates, while up to one third of men may have microscopic
signs of the disease at age 50. But far fewer will actually die of prostate
cancer. Watchful waiting means that when cancer is detected, no immediate
treatment is given, and the patient is instead monitored for signs that
his prostate cancer is progressing. The approach is based on the premise
that early prostate cancer may grow so slowly that it will never become
a serious health threat; studies have shown that men with early cancer
confined to the prostate gland can live years without signs of disease.
But in the US, the past two decades have seen a sharp increase in surgery
to remove the prostate gland--referred to as radical prostatectomy--despite
the fact that it has been unclear whether it extends the lives of men
with cancer confined to the prostate.
"There's been a lot
of debate, a lot of doubt, about whether it's necessary to treat prostate
cancer at its earliest, most curable stage," Dr. Patrick C. Walsh, a prostate
cancer expert at Johns Hopkins Hospital in Baltimore, Maryland, said in
an interview with Reuters Health. But these new findings, from two studies
of men in a long-range Scandinavian trial, provide "clear evidence" that
surgery for localized prostate cancer cuts men's risk of dying from the
disease, according to Walsh. In fact, he said, he was "absolutely shocked"
to see such a survival advantage emerge within the 8-year follow-up of
the study patients. According to Walsh, the benefit should only grow over
time. Walsh wrote an editorial accompanying both reports in The New England
Journal of Medicine.
In one study, researchers
found that men with localized prostate cancer who underwent radical prostatectomy
were about half as likely to die of prostate cancer over 8 years than
men in the watchful-waiting group. Overall, just under 9% of the 348 men
in the watchful-waiting group died of prostate cancer, compared with 4.6%
of the 347 men who received surgery. However, the risk of death from any
cause was comparable in both groups. The reason, for now, is unclear,
the study's lead author told Reuters Health. "Our main hypothesis is,
so far, that this is a chance finding," said Dr. Lars Holmberg of the
Regional Oncologic Center in Uppsala, Sweden. The second study, also led
by Holmberg, found that impotence and urinary incontinence were common
problems after radical prostatectomy, but many men in the watchful-waiting
group also reported these conditions. Eighty percent of surgery patients
had erectile dysfunction, as did 45% of watchful-waiting patients--which,
according to Holmberg's team, could have been due to growing tumors in
some cases. Watchful-waiting patients were also more likely to have an
obstruction blocking urinary flow. And despite their higher rate of impotence
and urinary problems, patients who received surgery rated their well-being
and quality of life as high as the other men did, the researchers found.
"We now have more
secure information that (surgery) diminishes the risk of dying from prostate
cancer, and we know more about the pattern of side effects both for watchful
waiting and surgery," Holmberg said. Walsh pointed out that men in the
Scandinavian trial did not routinely receive so-called nerve-sparing surgery,
a more recent advance in radical prostatectomy that can save the nerves
that control erection in some men. More men might have avoided impotence
had the technique been more widely used. But Walsh also emphasized that
there are men for whom watchful waiting is the best course, including
more-elderly men and those with serious co-existing illnesses--in general,
he explained, men whose life expectancy is less than 10 years. Some men
with very early cancer caught through PSA screening may also want to opt
for watchful waiting. According to Holmberg, much depends on where a patient's
priorities rest--whether survival rates or the risk of certain treatment
side effects weigh more heavily. "The doctor has to probe the patient's
preferences really carefully and discuss the options openly," he said.
[Top]
High-Fat
Diet May Foster Prostate Cancer Spread (Reuters Health-02/09/2002)
New research has
linked a high-fat, high-calcium diet to an increased risk of advanced
prostate cancer. And higher total calorie intake, the researchers found,
appeared to boost the risk of both localized and more advanced prostate
cancer. This suggests that modifying diet after prostate cancer treatment
could help reduce the risk that cancer will return, according to Dr. Alan
Kristal from the Fred Hutchinson Cancer Research Center in Seattle, Washington,
and colleagues."Our findings clearly show decreased risk for late-stage
disease in men with diets that are low in fat and moderate in calcium,
perhaps because these diets slow progression of prostate cancer into more
aggressive disease," Kristal said in a statement. "For men diagnosed with
early-stage prostate cancer, this finding could be important because it
suggests that moderating fat and calcium consumption may reduce the risk
of cancer recurrence following treatment," he added.
Kristal and colleagues
collected data on 605 men with prostate cancer and on 592 healthy men.
All were 40 to 64 years old. The researchers investigated whether prostate
cancer risk might be linked to total dietary energy, fat, calcium and
vitamin D. Study participants filled out questionnaires about their diet
during the past 3 to 5 years, either before their prostate cancer diagnosis
or before they entered the study, according to the report in Cancer Epidemiology,
Biomarkers and Prevention.
Higher calorie intake
was linked to an increased prostate cancer risk, the investigators found.
Compared with the lowest level of energy intake of fewer than 1,322 calories
per day, men with the highest calorie intake--2,439 calories daily or
more--were about twice as likely to develop local or more advanced prostate
cancer. Fat intake was associated only with regional/distant, or more
advanced, cancer. Men with the highest fat intake had about double the
risk of developing advanced prostate cancer compared to men with the lowest
intake. While higher calcium intake was associated with a 7% increased
risk of localized prostate cancer, the risk of advanced cancer was more
than doubled in these men compared to men with the lowest calcium intake.
There was no association between prostate cancer and vitamin D or with
omega-3 fatty acid intake, the authors add. "Our interpretation of these
results is that high-energy intake increases prostate cancer risk overall,
while high dietary fat and calcium intakes increase the risk of more clinically
significant, advanced stages of the disease," Kristal and colleagues conclude.
[Top]
Surgery,
Radiotherapy Equivalent for Localized Prostate Cancer (Reuters Health-30/08/2002)
For patients with
clinically localized prostate cancer, radical prostatectomy and external-beam
radiotherapy are equally effective, results of a single-center study suggest.
Dr. Patrick A. Kupelian, now of M.D. Anderson Cancer Center Orlando, and
colleagues at the Cleveland Clinic determined biochemical relapse-free
survival rates for 1054 men who underwent radical prostatectomy and 628
who underwent external-beam radiotherapy for localized prostate cancer.
Eight-year biochemical relapse-free survival rates for surgery and radiotherapy
were similar, 72% and 70%, respectively, the team reports in the Journal
of Clinical Oncology.
"Intrinsic tumor
characteristics seem to be more important than treatment modality in 8-year
biochemical-free relapse rates after radiation or surgery," they write.
"Biochemical failure rates are primarily determined by pretreatment PSA
levels, biopsy Gleason scores, clinical T-stage, and for radiotherapy
cases, radiation dose," Dr. Kupelian told Reuters Health.
The data also show
that tumors treated with radiotherapy are more advanced compared with
tumors treated with prostatectomy. But "the chances of recurrence (typically
determined by PSA elevations after treatment) at 8 years are similar after
either surgery or radiation," he said. PSA profiles, a measure of failure,
after radiotherapy and surgery are different, he said. "PSA levels are
undetectable after surgery, whereas PSA levels after radiotherapy are
expected to be low and stable. Defining a failure by rising PSA levels
or by a certain threshold (0.5 for this analysis), the cure rates after
either prostatectomy or high-dose radiotherapy were the same. This indicates
that the treatments are equivalent, independent from the failure definition
used," Dr. Kupelian explained. Finally, Dr. Kupelian said, for patients
undergoing radiotherapy, "this paper clearly shows that low radiation
doses (<72 Gy) result in inadequate cure rates. Doses exceeding 72 Gy
should be delivered if reasonable cure rates are to be expected with radiotherapy."
The investigators
add that longer follow-up is needed to see if the two treatment modalities
remain equivalent at the 10-, 15-, and 20-year mark. In an editorial in
the journal, two oncologists from Memorial Sloan-Kettering Cancer Center
in New York point out that the findings support those of previous studies
comparing radiotherapy to prostatectomy for localized prostate cancer.
"The strength of this report is that the outcome of patients who received
radiation therapy delivered to an optimal dose was comparable to that
of patients treated with surgery," Drs. Michael J. Zelefsky and Steven
A. Leibel add.
[Top]
Findings
Support PSA Tests for High-Risk Men (Reuters Health-09/08/2002)
French scientists
say their research findings support targeted prostate cancer screenings
for men with a family history of the disease. Currently, the American
Cancer Society recommends annual prostate specific antigen (PSA) testing
and a rectal exam beginning at age 50-and at age 45 for African Americans
and men with a family history of the disease, who face a higher risk.
Several other scientific and medical groups do not recommend routine prostate
cancer screening.
PSA is a protein
produced by the prostate gland. PSA levels above 4 nanograms per milliliter
(ng/mL) of blood can signal prostate cancer, but not always--sometimes
a rise in PSA is due to another cause, and sometimes cancer can occur
without a rise in PSA. About 20% of aggressive prostate tumors are found
in men with normal PSA levels. In the current investigation, lead author
Dr. Antoine Valeri of Center Hospitalier Universitaire in Paris and colleagues
evaluated PSA levels in 442 men who had a father or brother with prostate
cancer. All were between the ages of 40 and 70. They reported the findings
in The Journal of Urology.
Two men in the 40-
to 49-year-old age group had PSA levels above 4 ng/mL, the authors found.
One of these men was diagnosed with prostate cancer. Among men aged 50
to 70, 25 had a PSA greater than 4 ng/mL, and prostate cancer was diagnosed
in 9 of these individuals. "The proportion of relatives with PSA greater
than 4 ng/mL and prostate cancer detection...was significantly higher
in first degree relatives with early onset prostate cancer in the family
at ages younger than 65 years," the authors write. "Our results emphasize
the usefulness of PSA screening in high risk families," Valeri and colleagues
state. They add that more research is needed before earlier prostate cancer
screening can be justified, and that more study is necessary to determine
how often PSA tests should be done in men from high-risk families.
[Top]
Firefly
Glow Used to Track Prostate Cancer Spread (Reuters-22/07/2002)
The substance that
gives fireflies their glow can be used to detect the spread of prostate
cancer in mice--technology that could eventually be used to improve cancer
treatment for humans, according to new research. "Once you know where
the cancer is, you have a handle on how to treat it. It's much better
than treating the whole body with chemotherapy," Dr. Lily Wu, assistant
professor of urology and pediatrics at the University of California at
Los Angeles, said in an interview. Prostate
cancer patients who undergo surgery are then monitored for blood levels
of "prostate-specific antigen," or PSA, a protein marker of the cancer.
"If PSA shows up, it's an ominous sign because it means the cancer has
come back, but there is no way to detect where the cancer is," Wu, lead
author of the research study, explained. By attaching light to cancerous
cells "we are able to say aha, it's over there and then go after it,"
she added.
Prostate cancer is
the second leading cause of cancer deaths in American men. The UCLA researchers
engineered a virus that can identify prostate cancer cells based on the
PSA protein. By using the virus to deliver the substance that makes fireflies
glow, they were then able to identify, through high-tech imaging, prostate
cancer cells in primary tumors as well as distant organs. The imaging
technique could be used to diagnose the progress of cancer therapies.
The next step would be to attach gene-based therapies to the virus, which
would act as a vehicle to deliver the toxic treatment directly to the
prostate cancer cells and, hopefully, kill them, Wu said. Despite high
expectations created by major breakthroughs in cracking genetic codes,
the use of gene therapy to restore healthy gene activity is still in early
stages and clinical trials have been closely scrutinized since the death
in 1999 of a teenage trial volunteer.
"This could make
any kind of gene therapy much safer, and we wouldn't be doing it blindly,"
Wu said. The UCLA study, published in Nature Medicine, showed that three
weeks after tumor-bearing mice were injected with the virus, an imaging
camera could locate and illuminate small groups of cancer cells on the
spine and the lung. Wu said the gene-based tracking system could potentially
be used to detect the spread of many types of cancer. "The control element
we used is prostate cancer-specific, but it could be swapped with other
controls," the researcher said. "The idea would be to image and deliver
side-by-side a toxic gene to the cancer that would not harm surrounding
healthy cells," Wu said.
Experimental gene-therapy
treatments for prostate cancer are being studied in clinical trials, but
they have yet to reach advanced stages of development. Doctors administering
gene therapy now have no way to determine quickly that it reaches the
cancer cells it's targeting. "This discovery allows us to more rapidly
assess how cancers that are growing in animals respond to various treatments,
and, ultimately, will allow for the more rapid development of therapies
to treat advanced prostate cancer," said Dr. Kenneth Pienta, director
of urologic oncology at the University of Michigan Medical Center. Although
the camera detected the "hot spots" in animal models, a different system
will be needed to do the same thing in the much larger human body, Wu
said. To do that, the UCLA researchers are developing a system using positron
emission tomography, or PET scanning, she said. Wu estimated that the
gene-based delivery system could be tested in humans within three to five
years.
[Top]
Adding
Androgen Suppression to Radiotherapy Improves Prostate Cancer Survival
(Reuters Health-12/07/2002)
In patients with
locally advanced prostate cancer, radiotherapy plus immediate androgen
suppression provides significantly better survival outcomes than radiotherapy
alone, according to a report published in The Lancet. Dr. Michel Bolla,
from the University Hospital in Grenoble, France, and colleagues assessed
the outcomes of 415 patients who, between 1987 and 1995, were randomized
to receive external irradiation alone or followed by immediate androgen
suppression. All of the men had T1-2 tumors of WHO grade 3 or T3-4 N0-1
M0 tumors. The median followup period was 65.7 months. Both groups received
50 Gy radiation to the pelvis over 5 weeks and 20 Gy as a prostatic boost
over 2 weeks.In
the androgen suppression group, patients received subcutaneous injections
of the luteinising-hormone releasing hormone (LHRH) analogue goserelin
every 4 weeks for 3 years starting on the first day of irradiation. In
addition, these patients received daily doses of the steroidal antiandrogen
cyproterone acetate for one month starting 1 week before goserelin therapy
began.
The 5-year clinical
disease-free survival rate in the androgen suppression group was 74% compared
with a rate of only 40% in the radiotherapy-alone group (p=0.0001). The
corresponding 5-year overall survival rates in these groups were 78% and
62%, respectively (p=0.0002). Lastly, biochemical disease-free survival
was also significantly better in the androgen suppression group (p<0.0001).
"Androgen suppression provides a method to improve the outcome of external
irradiation alone, possibly by elimination of occult systemic disease,"
the researchers state. "Moreover, androgen suppression and external irradiation
seem to have an additive effect on local control by induction of apoptosis."
While androgen suppression does improve prostate cancer outcomes, the
optimal duration of such therapy remains to be determined, the authors
point out.
[Top]
Men
Know Family Cancer History, Don't Grasp Risk (Reuters Health-10/07/2002)
Just because a man
knows that family history can increase the risk of prostate cancer doesn't
mean he understands that his own risk increases after a family member
is diagnosed with the disease, new research suggests. Dr. Luc Cormier
of CHU Nancy-Brabois in France and his team found that 38% of men with
a brother or father with prostate cancer who knew that such a family history
ups the risk of developing the disease did not believe they had an increased
risk of the disease themselves. "Many men underestimated their own risk
of developing prostate cancer, even among those with good knowledge about
familial risk," the authors write.
Cormier and his colleagues
base their findings on surveys of 139 men aged 40 to 70, all of whom had
a brother or father who had been diagnosed with prostate cancer. The surveys
questioned respondents about their knowledge of prostate cancer, the benefits
of screening and their risk of developing the disease. Most of the men
who participated in the study were white, had graduated from college,
and lived in a household that earned more than $100,000 per year. More
than one quarter of respondents said they had more than one relative with
prostate cancer.
Although many men
did not accurately identify their own risk of prostate cancer, most were
quite knowledgeable about the condition: 98% answered at least half of
the questions about the disease correctly. Older men scored higher than
younger men. Most men said they supported the idea of screening and early
treatment for prostate cancer, the report indicates. More than three quarters
of respondents said they knew that family history was a risk factor for
prostate cancer, but of those, only 62% believed they had a higher than
average risk of the disease, Cormier's team reports in the journal Urology.
So why do so many
men not understand their own risk of prostate cancer? The answer, the
authors suggest, may lie in how men cope with stressful information. "This
perceived risk may be tempered by denial, a basic mechanism for coping
with stressful themes, in healthy and sick individuals," they write. On
a related note, a previous study regarding men's attitudes toward prostate
cancer screening found that even those who perceived themselves to have
a high risk were not more likely than others to get screened. "These men
have fatalistic behavior and/or they did not want to expose themselves
to the possibility of receiving information that might support this belief,"
the researchers note. Although the majority of the men included in the
study did, in fact, realize that prostate cancer can run in families,
"every single man in an at-risk family should recognize this as an important
risk factor," Cormier and his colleagues write. The investigators were
surprised to note that patients who said they had discussed prostate cancer
screening with their doctors were no more likely than others to understand
that family history increases the risk of disease. "This may be because
physicians did not talk about familial risk if they were unaware that
their patients belonged to at-risk families," Cormier's team suggests.
[Top]
Living
With Prostate Cancer (HealthScoutNews-07/07/2002)
No wonder the mention
of prostate cancer makes many men shudder. It's the second leading cause
of cancer deaths in American men, exceeded only by lung cancer. However,
if detected early, it's a very treatable cancer, even though the exact
cause isn't known and the side effects of some therapies can diminish
a man's quality of life. About 189,000 new cases of prostate cancer will
be diagnosed in American men this year, the American Cancer Society says.
Upon diagnosis, most men have a range of treatment options, from surgery
to radiation to hormone therapy. The best choice depends on their age,
health and concerns about side effects.
In general, surgery
or radiation treatment continue to be the best options, says Dr. Arnold
Kwart, chairman of the urology department at the Washington Hospital Center
in Washington, D.C. "Drug or hormone treatments are, by and large, palliatives,"
Kwart says. "If they're curative, they're curative maybe in about 10 percent
of patients."
The prostate is a
walnut-sized gland located just below a man's bladder, and its function
is to produce fluids for semen. Although men of any age can get prostate
cancer, it's most often found in those over 50, and more than 70 percent
of all cases are diagnosed in men over age 65. It's about twice as common
among black men as it is among white men. It's most common in North America
and western Europe, less so in Asia, Africa and South America, the cancer
society says. The best way to survive prostate cancer is to detect it
early. Although some 30,200 men in the United States are expected to die
of the disease this year, most cases are survivable with early detection,
doctors say. Men should begin regular screenings for prostate cancer at
age 50, says Dr. Judd Moul, a clinical urologist at Walter Reed Army Medical
Center in Bethesda, Md., and director of the Center for Prostate Disease
Research. If men belong to high-risk groups -- for example, if they're
black or have a history of prostate cancer in their family -- they should
start screenings as young as age 40, Moul says.
"The secret is picking
it up early," he says. The National Comprehensive Cancer Network says
that once prostate cancer is detected, the treatment options are:
Radical prostatectomy:
This is the removal of the entire prostate gland. Surgeons enter through
an incision in either the lower abdomen or between the scrotum and anus
to remove the gland, along with any apparently nearby cancerous tissue.
The main side effects of such surgery are incontinence and impotence.
While bladder control usually returns within a few weeks of surgery, up
to 35 percent of men report passing a small amount of urine while sneezing,
coughing, laughing or exercising. Between 2 percent and 5 percent of men
report more severe incontinence. Impotence is a more common side effect
of the surgery. For up to a year, most men will not be able to maintain
an erection. Moul says impotence can be limited if the surgeon is able
to perform a nerve-sparing prostatectomy, which leaves the nerves on either
side of the gland intact. "It's the gold standard, as far as treatments
go," he says. Under a normal prostatectomy, between 65 percent and 90
percent of men will become impotent, depending on their age. Nerve-sparing
surgery reduces the impotence rate to between 25 percent and 30 percent
for men under 60.
Radiation therapy:
Two options exist for this type of therapy, either external beam radiation
or internal radiation treatment. External beam radiation is much like
getting a standard X-ray, only for a longer time. Patients usually receive
treatment five days a week in an outpatient center for seven or eight
weeks, with each treatment lasting a few minutes. Internal radiation therapy
uses radioactive pellets the size of a grain of rice that are implanted
into the prostate. The radioactive materials are placed inside thin needles,
which are inserted through the area between the scrotum and anus, into
the prostate. The side effects of external beam radiation therapy include
diarrhea, colitis, frequent urination, a feeling of fatigue and impotence,
which can be temporary or permanent. Internal radiation therapy can cause
impotence, incontinence and bowel problems. Rectal problems such as burning,
pain and diarrhea may occur in up to 5 percent of patients and are difficult
to treat once they develop.
Hormone therapy:
This involves lowering male hormones, also known as androgens. The main
androgen is testosterone. Produced primarily in the testicles, androgens
cause prostate cancer cells to grow. Prostate cancers can shrink or grow
more slowly when androgen levels are lowered, but hormone therapy doesn't
cure the cancer. Male hormone levels can be lowered through orchiectomy
-- an operation to remove the testicles -- or through the use of drugs
to decrease testosterone. The drugs include luteinizing hormone-releasing
hormone (LHRH) analogs like leuprolide (Lupron) and goserelin (Zoladex),
which reduce the amount of testosterone in the body. There are also anti-androgens
like flutamide (Eulexin), bicalutamide (Casodex), and nilutamide (Nilandron),
which stop the body's ability to use androgens. Hormone therapy can cause
impotence, hot flashes and growth of breast tissue. A recent study by
the National Cancer Institute found men who had the therapy were more
than twice as likely to suffer impotence than men who didn't undergo the
treatment, and five times more likely to suffer hot flashes and breast
swelling.
In the end, all these
therapies might work best when combined together. Moul says that over
the last couple of years, more consideration has been given to treatments
that blend the available options. "It may make more sense to attack the
cancer through different means than relying solely on one form of therapy,"
he says.
[Top]
It's
Prostate Cancer -- Or Is It?-(HealthScoutNews-02/07/2002)
A large number of
men who are given the scary news that they have prostate cancer are being
rattled -- and perhaps treated -- unnecessarily, a new study suggests.
The diagnosis for those men is based on detection of high levels of prostate-specific
antigen (PSA), a molecule associated with the malignancy. The computer
study concludes that many of them -- 29 percent of whites, 44 percent
of blacks -- would be better off not knowing that diagnosis because they
would die of other causes before the cancer did any damage.
PSA testing was approved
by the U.S. Food and Drug Administration in 1986 as a way to monitor treatment
of prostate cancer. Starting in 1988, it has been used more and more for
detection, even though there is mixed evidence to say it works well for
that purpose. Diagnoses of prostate cancer rose sharply after the PSA
test went into widespread use. The study, appearing in tomorrow's issue
of the Journal of the National Cancer Institute, says a lot of those diagnoses
are doing more harm than good because they lead to men getting treatment
they don't need. "Considerable morbidity can be associated with treatment
for the disease," says study leader Ruth Etzioni, a biostatistician at
the Fred Hutchinson Cancer Research Center in Seattle.
The importance of
that conclusion is illustrated by some numbers. The American Cancer Society
estimates that 189,000 cases of prostate cancer will be diagnosed this
year. There will be 30,200 deaths, making prostate cancer the second leading
cause of cancer deaths in men. Many of those diagnoses will be made on
the basis of something other than the PSA test. To determine the effect
of PSA testing, Etzioni and her colleagues created a computer model using
government cancer registry data. "The reason we used a computer model
is that the real world is a very uncontrolled setting, with a lot of multiple
factors that can affect prostate cancer incidence," Etzioni says. "The
model allows us to understand one of those factors."
The model was based
on a hypothetical group of men aged 60 to 84. The estimated percentages
of over-diagnoses (higher for blacks than whites because they are more
susceptible to the cancer, for unknown reasons) were based on two factors:
Either the cancer would grow so slowly that it would not affect a young
man, or an older man would die of other causes before the cancer caused
a problem. Unfortunately, the model provides no guidance for a man who
is told his PSA level is high enough to require treatment, Etzioni says.
Men with high PSA levels are more likely to be diagnosed with the disease,
she says, but the PSA levels that indicate a real danger aren't known,
she says. "This has to be determined by molecular biology tools," Etzioni
says. "A lot of work is going into developing clinical models." The American
Cancer Society recommends a combination of PSA testing and a digital rectal
examination for men of average risk annually starting at age 50, "with
an explanation of the benefits and limitations" of the tests, says Dr.
Durado Brooks, director of prostate cancer for the society. "For high-risk
men, which we define as African-Americans and those with a family history
of the disease, we recommend the screening begin at age 45," Brooks says.
[Top]
Scientists
Find Gene Linked to Testicular Cancer (Reuters-05/06/2002)
An overactive gene
that has been linked to testicular cancer could one day be monitored in
men who are at risk and reprogrammed so it is kept under control, researchers
said. Scientists at Duke University found that a gene, called hiwi, was
up to 16 times more active in men with testicular cancer than in healthy
patients. Finding the gene, the first to be directly associated with testicular
cancer, could allow researchers to watch for the disease and to help stop
tumors from growing. "We still have a way to go before we completely understand
the major cause of this type of cancer," Haifan Lin, who led the study,
said in a telephone interview. "But there also is the potential for long-term
therapeutic applications in that hopefully some cancers can be cured by
reducing the activity of this gene," he said.
The American Cancer
Society estimated that more than 7,500 males will be diagnosed this year
with testicular cancer and about 400 will die from it. Testicular cancer
is the most common form of cancer among white men between the ages of
15 and 45, the agency said. Still, the American Cancer Society said 95%
of those who get this type of cancer will live more than five years, up
from 79% in the mid-1970s. Survivors of the disease include star cyclist
Lance Armstrong, who was diagnosed in 1996. Lin and his colleagues studied
tissue samples from 35 males who had developed testicular cancer. In one
form of the cancer, they found that 12 of the 19 patients, or about 63%
of the group, expressed unusually high levels of the hiwi gene. Several
other genes have been associated with testicular cancer, but only at levels
of 10% or lower, Lin said.
Testicular tumors
occur in reproductive stem cells where levels of the hiwi gene are high.
The cells continue to rapidly divide, leading to one form of the cancer
known as seminoma. A second type is called nonseminoma, a more aggressive
type of the cancer that can quickly spread to the body's lymph nodes.
These tumors do not express abnormal levels of the hiwi gene. Even though
the hiwi gene is the first to be directly associated with testicular cancer,
Lin is optimistic that other genes could be discovered that play a role
in the disease. Some researchers believe chromosome X and chromosome 19
could offer the best chances to pinpoint further genes associated with
the cancer.
[Top]
Clues
on Vitamin E's Anti-Prostate Cancer Effects (Reuters Health-29/05/2002)
Vitamin E appears
to protect against prostate cancer, and new research shows it may do so
by interfering with two proteins that are associated with the disease.
Researchers based at the University of Rochester in New York found that
adding vitamin E to prostate cancer cells inhibits the production of a
receptor for testosterone, called the androgen receptor (AR), which is
needed in order for the cancer to grow and develop. "The fewer ARs there
are in a (prostate cancer) cell, the less capable the remaining ARs, no
matter how they are activated, are to turn on the genes that stimulate
(prostate cancer) growth and progression," study author Dr. Edward M.
Messing told Reuters Health. "Thus, this can be combined with other AR
inhibiting strategies to eliminate AR activity in (prostate cancer) cells,"
he added.
In the US, prostate
cancer is the second-leading cause of death among men. Previous research
has shown that vitamin E can protect against the development of prostate
cancer, reducing risk from 18% to 12% among male smokers. However, researchers
remained puzzled about how vitamin E, and not other antioxidants, lowered
the risk of prostate cancer. Now, the authors of the current study, led
by Dr. Shuyuan Yeh, report that vitamin E inhibits the expression in prostate
cancer cells of prostate-specific antigen (PSA), a protein that is often
elevated in the disease and used as a marker for early detection. The
investigators also note in the May 28th issue of the Proceedings of the
National Academy of Sciences that the vitamin can prevent cells from making
androgen receptors.
In an interview
with Reuters Health, Messing said he suspects the benefits of vitamin
E stem from its interference with AR production. "The only thing we know
of in 2002 that turns on PSA is an activated AR," he said. Moreover, the
researcher added, stopping the production of AR will halt the expression
of all other genes that are activated by AR, which can also influence
the development of prostate cancer. "While PSA serves as a good marker
molecule of AR activity, more importantly the genes responsible for (prostate
cancer's) growth, invasion and metastases, many of which depend upon an
activated AR to turn them on, will be down-regulated or totally silenced
as well," he noted. All of the currently available treatments that aim
to inhibit AR in prostate cancer cells primarily focus on preventing testosterone
from binding to the receptor, Messing explained, but do not have long-term
benefits, and can produce serious side effects in other parts of the body.
This is the first study to show how an agent can, in fact, specifically
inhibit a prostate cancer cell's ability to manufacture AR, Messing added,
and the vitamin appears to affect mostly prostate cancer cells. Vitamin
E might work best when administered with other natural treatments that
also appear to protect against prostate cancer, such as vitamin D and
selenium, the authors write. In addition, combining vitamin E with an
anti-androgen cancer drug called hydroxyflutamide prevented growth of
prostate cancer cells better than either treatment did alone.
[Top]
Putting
Cancer in Deep Freeze-(HealthScoutNews-17/05/2002)
Doctors have been
freezing malignant tumors for years with cryosurgery, but hardy cancer
cells sometimes resist the arctic blasts and stay inside the body to cause
more trouble later. Now researchers say a combination of cryosurgery and
chemotherapy may wipe out all the malignant cells. "Cryosurgery is a very
effective method for treatment of cancer, and it will become more effective,"
predicts study author Boris Rubinsky, a professor of bioengineering and
mechanical engineering at the University of California, Berkeley. "I anticipate
that some doctors will use this procedure as soon as this study goes into
print." Doctors began to freeze tumors in the 1960s, but they were hampered
by not being able to see inside the body. The procedure has become more
common as scientists have developed probes that direct liquid nitrogen
or argon gas to freeze tumors inside the body, and ultrasound machines
now show doctors where they're going.
Doctors use cryosurgery
to treat prostate cancer and liver cancer. Experiments are being done
on pancreatic cancer and bone cancer. "You inject it into the tumor, and
you keep freezing until the tumor is frozen," Rubinsky says. "The frozen
tissue remains in the body, and the immune system removes it [if it is
dead]." However, there can be a big problem. The probes turn tumors into
"ice balls," but the temperatures vary from the core (as low as 220 degrees
below zero Fahrenheit) to the outer edges (as high as 40 degrees below
zero Fahrenheit). So, some cells on the edges survive the cold. Doctors
often will freeze nearby healthy tissue to get at the edges of a tumor,
but that technique can create its own problems because healthy nerves
and muscles are damaged, and that can lead to incontinence or impotence.
Rubinsky and a colleague
at France's Institut Gustave-Roussy tried to replicate what happens in
humans by freezing skin cancer cells in test tubes and then treating them
with bleomycin, a chemotherapy drug also known by the brand name Blenoxane.
Their findings will appear in next week's British Journal of Cancer. Numerous
cancer cells remained after freezing, but subsequent treatment with bleomycin
destroyed most or almost all of them, depending on how much of the drug
was used. The combination treatment works because the surviving cancer
cells are weakened by their freezing and become more vulnerable to bleomycin,
says Dr. Israel Barken, chairman and medical director of the Prostate
Cancer Research and Education Foundation, which helped fund the research.
"It gives you the opportunity to be less aggressive with chemotherapy,
so the tissue around [the tumor] won't get damaged," Barken says. He cautions
that animal studies must be done to determine the full effectiveness of
the treatment. "This is a very preliminary stage," he notes. But Rubinsky
says that doctors can begin using the combination treatment immediately
because the federal government has already approved cryosurgery and bleomycin
for use separately to treat cancer. "There is no impediment," he adds.
[Top]
Prostate
on Course to Become Top UK Male Cancer-(Reuters-28/05/2002)
Prostate cancer is
on course to become the most common men's cancer in Britain in the next
3 years, health experts said. Cases of the disease have doubled in the
past 20 years and scientists predict the numbers will continue to rise
as the population ages and more men are tested for the illness. "The incidence
of prostate cancer in this country has increased more rapidly than we
had expected," Professor Colin Cooper told a news conference. The head
of Britain's first dedicated male cancer research unit at The Institute
of Cancer Research described the disease as an enigma. Although more men
are being diagnosed with the disease, fewer are dying from it. Up to two-thirds
of men with the illness may also not need treatment, which can cause side
effects such as impotence and incontinence, but scientists do not know
enough about the disease to determine whether or not a patient has an
aggressive cancer. "What this means in reality is that many men could
receive treatment who may not need it. On the other hand, if prostate
cancer is not detected early by PSA testing, some men will have developed
advanced, incurable disease," according to Dr. David Dearnaley, a male
cancer expert at the institute.
More men are being
diagnosed with the disease because the PSA (prostate-specific antigen)
test can detect the early signs. The test is widely available in the United
States and in Britain men over 50 years old can have it on request. Most
cases of the disease are diagnosed in men in their 70s. Around 22,000
cases of prostate cancer are diagnosed in Britain each year and 9,500
men die of the disease annually. Most fatal cases are not detected until
the disease is advanced. As an alternative to surgery or radiation, doctors
at the institute have started a trial of an Active Surveillance programme,
which monitors the disease through tests and biopsies. "If there are signs
of progression, the man can proceed to either surgery or radiotherapy,"
said Dr. Chris Parker, who is involved in the trial. A similar study by
Canadian researchers showed that less than one quarter of the men in the
programme required treatment. Scientists are also measuring oxygen levels
in tumours to detect the most serious cases of the disease. Cancers with
lower oxygen levels are thought to be more likely to spread.
[Top]
New
Screens May Find Early Prostate, Ovarian Cancer (HealthScoutNews-02/04/2002)
When it comes to detecting
and treating cancer, the old saying "better late than never" generally
doesn't apply. Fortunately, two studies in the Journal of the American
Medical Association offer hope for early warnings on two major killers:
ovarian cancer and prostate cancer. Together, these diseases account for
more than 50,000 deaths a year in the United States alone.
In the first study,
Dr. Arul Chinnaiyan and his colleagues at the University of Michigan used
"DNA chip" technology to find genes that become overactive in prostate
cancer. The disease is the most common cancer in men, diagnosed in 180,000
Americans each year. Although it can be cured with surgery and other therapies,
40,000 in this country die of prostate cancer annually. Chinnaiyan's group,
which earlier identified two genes that may help doctors predict the aggressiveness
of prostate tumors, found a third gene, called AMACR, which is elevated
exclusively in a cancerous gland. "It's probably the best marker that
we've seen that distinguishes prostate cancer from benign prostate [enlargement],"
Chinnaiyan says. "It's very specific for cancer, and we think it has a
high potential for being a diagnostic marker."
AMACR produces an
enzyme, a-methylacyl-CoA racemase that helps cells break down fatty acid
molecules. Chinnaiyan says it's not clear exactly what role the enzyme
plays in prostate cancer, although tumors usually require more fatty acid
metabolism to keep up with their frenetic growth. Chinnaiyan says AMACR,
which is easy to test for, could help doctors facing a fuzzy prostate
biopsy. Such ambiguity occurs in about 15 percent to 20 percent of samples,
he says.
However, the Michigan
researchers also hope the gene might be useful as a screening test. If
so, it would have an advantage over the current prostate screening exam,
prostate-specific antigen (PSA). This test picks up elevations in a blood
protein shed by prostate tumors. Unfortunately, it's produced by benignly
enlarged glands, too, leading to much unnecessary treatment. AMACR, on
the other hand, appears only to be elevated in the presence of cancer,
so a positive result would mean a tumor. The question, Chinnaiyan says,
is whether it can be detected in blood. "We're starting to look in serum
to see if it's shed," he adds.
The alphabet soup
combination of PSA and AMACR has "a lot of potential" as a screening test,
says Dr. Mark Rubin, a co-author of the paper. In addition, the researchers
have been finding other genes that in concert could be able to greatly
enhance the ability of doctors to find and treat prostate cancer.
Dr. Jonathan W. Simons,
director of the Winship Cancer Institute at Emory University in Atlanta,
calls the latest discovery "an important result." "Everybody knows the
PSA test is incredibly helpful, but since it received [Food and Drug Administration]
approval we've been struggling to improve on it," Simons says. "I can't
wait to use [the new gene test] in my patients."
The new test is not
yet on the market, although Chinnaiyan and his colleagues are seeking
to patent AMACR and the other prostate cancer genes they uncover.
In the second study,
a team led by Harvard Medical School oncologist Samuel Mok found a protein
that appears to be sharply elevated in women with ovarian cancer. Mok's
group looked for concentrations of the protein osteopontin in 144 women
undergoing treatment for pelvic tumors, some benign, some cancerous. Osteopontin
earned its name because it plays a role in the formation and erosion of
bone, but it has also been found in many other tissues throughout the
body. Osteopontin levels were roughly four times higher, on average, in
women with ovarian cancer than in those without the disease, the researchers
say. They were also elevated, though somewhat less so, in ovarian cancer
patients compared to women with benign tumors or to those with other forms
of reproductive cancers.
Ovarian cancer claims
15,000 lives a year in this country, largely because it is usually detected
in later stages. The five-year survival rate for the tumors is 95 percent
when found early, a figure that drops to just 30 percent when the cancer
is far advanced upon discovery.
[Top]
Love
Can Conquer Impotence: One Couple's Story-(Health Scout-26/03/2002)
For Virginia and Keith
Laken, treating Keith's prostate cancer was just the beginning. "We had
to redefine ourselves as to how our sexual relationship was going to be,
and Keith had to redefine himself regarding his manliness," says Virginia,
a communications consultant. "You need to understand that that's normal,
that you're going to most likely need help with that." The Minnesota couple
had been married more than 25 years and were enjoying their new empty
nest when Keith was diagnosed with prostate cancer at the age of 49.
Prostate cancer is
second to skin cancer as the most common cancer in men, according to the
American Cancer Society. An estimated 189,000 cases of prostate cancer
will be diganosed in the United States in 2002, and more than 30,000 of
them will be fatal. Although there are a number of effective treatments
for the disease, a large proportion (estimates range from 30 percent to
90 percent) of the men who undergo treatment will experience temporary
or permanent impotence.
Worried that he would
become one of these statistics, Keith first opted for no treatment at
all. He later changed his mind and in 1995 underwent a radical prostatectomy
to remove his prostate gland.
The Lakens advise
couples confronting impotence to:
- communicate and
candidly share information with each other.
- recognize the
need to treat the mind as well as the body; seek help from support groups
and mental health experts.
- accept that emotional
states can swing from high to low unexpectedly, especially during the
first year of recovery.
[Top]
Hormone
Therapy for Prostate Cancer May Not Be Worth It (HealthScoutNews-19/03/2002)
If you're a man in
the early stages of prostate cancer therapy that reduces your level of
male hormones may be more trouble than it's worth. A new study from the
National Cancer Institute found men who had the therapy were more than
twice as likely to become impotent and five times more likely to suffer
hot flashes and breast swelling, when compared to men who didn't opt for
the treatment. Worse, that suffering may be in vain because there's no
proof that androgen deprivation therapy (ADT) actually does these men
any good when used alone, says lead author Arnold L. Potosky, a researcher
at the institute. The study appears in the Journal of the National Cancer
Institute.
"There are a lot
of men who are receiving androgen deprivation therapy as a sole therapy
for localized prostate cancer, despite a lack of any evidence that in
that specific situation it can prolong survival, compared to any other
therapy or compared to no therapy," Potosky says. He and his colleagues
analyzed data from 661 men diagnosed in 1994 and 1995 with prostate cancer
that hadn't spread beyond the prostate. None had surgery or radiation
for the cancer. The men, from six different areas of the United States,
were tracked for a year after diagnosis.
The authors found
that 245, or 37 percent, of the men received ADT. After one year, 80 percent
of the men who received ADT reported they'd become impotent, compared
to 30 percent of men who didn't receive treatment. Men who received ADT
were also five times more likely to report breast swelling and hot flashes.
While ADT caused these complications, 56 percent of the men receiving
ADT said they believed they were free of their cancer, while only 45.3
percent of the men receiving no therapy reported the same relief, the
study found.
The goal of ADT is
to lower or eliminate male hormones, which promote tumor growth in the
prostate. There are several ways to accomplish that, including removing
the testicles or having patients take the female hormone estrogen. Since
the early 1990s, luteinizing hormone-releasing hormone (LHRH) agonists
have become a common form of ADT. LHRH agonists, given by regular injection,
prevent the testicles from producing testosterone. In this study, LHRH
agonists were given to 78 percent of the men who underwent ADT.
The authors note
that about 160,000 American men each year are diagnosed with localized
prostate cancer. More than half of those men are treated with either surgery
or radiation. It was estimated in 1996 that about 20,000 American men
undergo the more conservative ADT treatment each year and that figure
is likely much higher now, Potosky says. "So just the prevalence of this
therapy is an interesting finding in and of itself, and that hasn't been
documented on a population-wide basis in the U.S.," he says.
The LHRH agonists
have made ADT a simple method of treatment. However, Potosky stresses
there are no definitive studies to show the therapy improves the length
or quality of life for men with localized prostate cancer. "So we don't
really know if it's beneficial in terms of survival, but it certainly
has a down side in terms of sexual impairment and reduced physical function,
that we document in this paper, within the first year of its use," Potosky
says. He hopes this study stimulates clinical trials to establish whether
ADT is effective when used as the sole treatment for localized prostate
cancer.
Another expert agrees
this area needs more research. "ADT alone isn't recommended for patients
with localized prostate cancer anywhere in the medical literature. It
is an unproven use of therapy," says Dr. James A. Talcott, assistant professor
of medicine and director, Center for Outcomes Research, at the Massachusetts
General Hospital Cancer Center in Boston. One important discovery is the
study shows the large number of American men receiving ADT as primary
treatment for their prostate cancer, says Talcott, who wrote an editorial
that accompanies the article. "They really need to understand that androgen
deprivation therapy has down sides, and those down sides aren't well-studied
and the drugs are being used in situations beyond where they've been proven
effective," Talcott says.
[Top]
Painkillers
may prevent prostate cancer-(Times of India Online-12/03/2002)
Regular use of Aspirin,
Ibuprofen and other common painkillers appear to protect against prostate
cancer among older men, Mayo Clinic researchers said. Men over age 60
who took a daily dose of one of the drugs known collectively as non-steroidal
anti-inflammatory drugs (NSAIDs) were half as likely to develop the disease,
which is the second-leading cancer killer among US men with more than
30,000 deaths expected this year.
The five-and a-half-year
study of 1,362 white men in Minnesota found 4 per cent of those who took
the drugs developed prostate cancer, versus 9 per cent of those who did
not. The older the patient, the more pronounced the protective effect
of the drugs, the study said.
But Mayo Clinic researcher
Rosebud Roberts, writing in the journal Mayo Clinic Proceedings, cautioned
that the results were inconclusive and needed confirmation. "We also need
to determine the duration and dosage use that provides protection against
prostate cancer, and to better understand the biologic mechanisms underlying
the association between NSAIDs and prostate cancer," Roberts said. In
addition, regular use of such drugs can be harmful, causing stomach problems
and liver damage in some people. Roberts said that previous studies had
shown NSAIDs offer protection against breast cancers in women and against
colon cancer.
The study, part of
a larger survey, was also focused solely on white male subjects. "African
American men have the highest risk of prostate cancer. We need to complete
additional research to determine if these findings are applicable to them,"
Roberts said.
[Top]
Tomato
products reduce risk of prostate cancer-(Associated Press-06/03/2002)
A diet rich in tomato
sauce, ketchup and other tomato-based products containing a powerful antioxidant
can lower the risk of prostate cancer, a new study says. Researchers analysed
the food choices and prostate cancer histories of more than 47,000 men
and found that those who ate at least two meals a week containing tomato
products lowered their risk of prostate cancer by 24 to 36 per cent. Dr
Edward Giovannucci of Brigham and Women's Hospital and the Harvard School
of Public Health, the first author of the study, said it supports earlier
research involving foods, particularly tomato products, that were high
in lycopene, a powerful antioxidant. A report on the study appears in
the Journal of the National Cancer Institute.
"These most recent
finding add support to the notion that a diet rich in tomatoes and lycopene-containing
foods, as well as other fruits and vegetables, may reduce the risk of
prostate cancer, said Giovannucci. He said that lycopene is thought to
protect against cancer by absorbing oxygen-free radicals, which are chemicals
created during metabolism that can damage the genetic structure of cells.
The finding is based on data from the Health Professional Follow-Up Study,
a project that followed the health history and dietary habits of 47,000
men, aged 40 to 75, from 1986 to 1998 During that period, 2,481 of the
men developed prostate cancer.
Dietary questionnaires
in the study included such food items as tomatoes, tomato sauce, tomato
juice, pizza, watermelon and pink grapefruit, along with salsa, ketchup
and other tomato-based condiments. When the data was adjusted for the
effects of other life style factors, the researchers found that tomatoes,
particularly those that had been cooked, were beneficial against prostate
cancer. "Spaghetti sauce was the most popular" and also seemed to give
the most protection, said Giovannucci. He said that cooking raw tomatoes,
as is done to make spaghetti sauce, may break down cell walls of the fruit
and allow the body to absorb more of the lycopene. Giovannucci emphasised
that tomato-based products should be only a small part of a well-rounded
diet that includes other fruits and vegetables and avoids an excess of
fats.
Jo Ann Carson, a
clinical nutritionist at the University of Texas, Southwest Medical Center
in Dallas, said the study "is an example that what we eat affects our
risk of cancer. The study also supports the idea that foods rich in antioxidants,
rather than vitamin pills, provide the most cancer protection. Eating
the whole foods seems to give a beneficial combination that would be lacking
in supplements," Carson said.
[Top]
Researchers
Link Gene To Hereditary Form Of Prostate Cancer -(Cancer Info-24/01/2002)
For the first time,
scientists have publicly reported that they found a gene on chromosome
1 that's associated with an inherited form of prostate cancer in some
families. The findings were released on the Internet today in the Advance
Online Publication of Nature Genetics by researchers at the National Human
Genome Research Institute, Johns Hopkins Medical Institutes, the Cleveland
Clinic and their collaborators.
Ever since 1992,
when Johns Hopkins researchers first showed that some forms of prostate
cancer could be inherited, scientists have intensely searched for specific
genes that cause the disease. In 1996, NHGRI scientists, in collaboration
with researchers at Johns Hopkins and in Sweden, studied 91 high-risk
prostate cancer families and mapped the first hereditary susceptibility
to prostate cancer to a region of chromosome 1 that they called the Hereditary
Prostate Cancer 1 Region, or HPC1. Since then, these and other research
teams have mapped prostate cancer susceptibly genes to two other parts
of chromosome 1, as well as to chromosomes 17, 20 and X.
Now, researchers
at NHGRI and Johns Hopkins have identified a specific gene called ribonuclease
L or RNASEL in the HPC1 region that contains mutations associated with
prostate cancer in some families with a history of the disease. The scientists
found mutations that inactivate the RNASEL gene. Scientists at the Cleveland
Clinic Foundation have been studying RNASEL for years and have shown that
it plays a role in defending cells from viruses and assists in normal
cell turnover or programmed cell death.
Inactivating this
cellular self-destruct mechanism through genetic mutation may explain
why some prostate cells become cancerous. Mutations in this one gene,
however, do not explain all forms of inherited prostate cancer, cautioned
John D. Carpten, Ph.D., an NHGRI cancer genomics researcher and the paper's
lead author, adding, "This is not the only gene involved in prostate cancer.
We know that mutations in any number of genes can lead to the development
of prostate cancer, and this gene possibly represents a new member in
the repertoire of prostate cancer genes."
These germline or
hereditary mutations often do not explain the so-called sporadic cases
that are not inherited. Sporadic prostate cancer is much more common and
is caused by genetic mutations that arise spontaneously in the genes of
prostate cells in adult males. In the United States, there is an approximately
16 percent likelihood that an adult male will develop prostate cancer
sometime in his life. Of the more than 189,000 cases of prostate cancer
diagnosed each year, researchers believe only about 9 percent are hereditary.
Despite these limitations,
said Jeffrey M. Trent, Ph.D., NHGRI's scientific director, chief of the
Cancer Genetics Branch and the paper's senior author, "The new finding
presents a tantalizing clue about the workings of the complex genetic
machinery that leads to this common cancer."
"It has been clear
for some time that hereditary factors play a major role in prostate cancer
risk," added Francis S. Collins, M.D., Ph.D., director of the National
Human Genome Research Institute. "The discovery of heritable inactivating
mutations in a specific gene is an exciting step towards understanding
the causes of this common and devastating form of cancer. Ultimately,
this should bring us closer to better diagnosis, prevention, and cure."
This discovery will
not immediately lead to new diagnostic tests or new treatments. "This
is not the breakthrough gene that is going to solve everything," said
Patrick C. Walsh, M.D., an author of the study and chairman of the James
Buchanan Brady Urological Institute at Johns Hopkins Medical Institutes.
But it does create a number of new research opportunities for better understanding
prostate cancer. Eventually, an improved understanding will lead to better
tests and treatments.
"We expect that there
will be multiple genes involved in prostate cancer," Trent said, " and
as we identify them, we should be able to put together a picture of the
factors that convert a normal prostate into the most common cancer in
men."
[Top]
Second
prostate cancer gene found-(Times of India Online-21/01/2002)
Scientists have identified
a second faulty gene that appears to make some families prone to developing
prostate cancer, a finding that someday might help doctors diagnose and
treat some cases of the disease. Only about 9 percent of prostate cancer
cases are hereditary, and the gene is related to only an unknown fraction
of these. It's not clear whether the gene, called RNASEL (pronounced ``R-N-ace-L''),
plays any role in nonhereditary cancers. The new work appears in the journal
Nature Genetics.
The previously identified
gene linked to hereditary prostate cancer, called HPC2-ELAC2, also appears
to be implicated in only a small fraction of cases. The new study was
done by a consortium of researchers from institutions including the National
Human Genome Research Institute in Bethesda, Md., the Johns Hopkins Medical
Institutions in Baltimore and the Cleveland Clinic. Further study of the
gene could help shed light on the biology of prostate cancer which might
give hints for developing new treatments.
In its normal form,
the RNASEL gene was previously known to make cells commit suicide under
some conditions, and that might explain the cancer connection, said study
co-author Robert Silverman of the Cleveland Clinic. One reason for a cell
to kill itself is that it's on the road to becoming cancerous. If the
RNASEL gene is defective and can't send its suicide signal, it loses its
ability to act like a brake on the disease, Silverman said.
Jeffrey Trent of
the genome research institute, senior author of the paper, said defective
versions of the gene might also make prostate cancer more aggressive.
Scientists screened
DNA from 26 families prone to prostate cancer and found two families in
which brothers with the disease had inherited mutated copies of RNASEL.
Such inherited mutations were uncommon in the general population, the
researchers found.
Timothy Rebbeck,
who studies prostate cancer genetics at the University of Pennsylvania
but didn't participate in the new study, called the work exciting because
RNASEL is only the second known gene to be implicated in hereditary prostate
cancer. While it appears responsible for only a tiny fraction of prostate
cancers, he said, that's probably the case for any inherited defect that
promotes the disease.
[Top]
Biotech
firm claims has found potential cancer drug-(Times of India Online-10/10/2001)
Myriad Genetics Inc.,
a biotechnology company that studies genes and proteins to discover new
drugs, said it has found a way to kill a wide range of cancer cells without
damaging healthy cells. Salt Lake City-based Myriad said its MPI-176716
compound causes cell death in several cancers, including prostate cancer
and T cell lymphoma. The target for MPI-176716 is a protein that has not
been explored previously, the company said.
If the human body
is working as it should, normal cells are destroyed after they serve their
function. If this process is damaged, cells may continue to divide and
grow, resulting in cancer. Myriad said it has found a way to induce cells
to destroy themselves if they are not doing it naturally. The company
said the process may help it develop drugs that don't harm healthy cells,
causing the kind of toxic side effects seen in treatments such as chemotherapy
or radiation.
[Top]
Necessity
Of Annual PSA Screening Questioned –(Cancer Page-08/08/2001)
Although the American
Cancer Society has recommended annual prostate-specific antigen (PSA)
screening since 1993, no studies have established this as the optimum
screening interval. Now, findings from a study by Dutch researchers
suggest that intervals as long as 4 years may be adequate.
In a study by Dr. Robert F. Hoedemaeker and colleagues, from Erasmus University
Rotterdam, the value of PSA screening was assessed in 4133 men, 55 to
75 years of age. All of the men underwent initial PSA screening
and slightly more than half underwent a second screening 4 years later.
After the initial screening, prostate biopsy was recommended for 27.3%
of men on the basis of a PSA level of 4 ng/mL or greater, abnormal digital
rectal examination, or abnormal transrectal ultrasound findings, the authors
state. At the second screening interval, biopsy was recommended
for 20.2% of men on the basis of PSA levels of 3 ng/mL or greater.
PSA values predicted the amount of tumour in biopsy specimens during the
first round of screening but not during the second round, the researchers
determined. "Our study shows a substantial decrease in both the amount
and the grade of screen-detected prostate cancers 4 years after an initial
prevalence screen," the investigators state. "Relatively few advanced
tumours were found after the 4-year interval" and "the frequency of prostate
cancer in needle biopsies dropped at high PSA ranges," they add.
The current findings "suggest that large prostate cancers with high PSA
values are effectively detected during a prevalence screen and that even
an interval of 4 years is not long enough for most large tumors to develop,"
the authors emphasize. "A screening interval of 4 years appears to be
short enough to constrain the development of large tumors, although it
is inconclusive whether this will result in a survival benefit," Dr. Hoedemaeker's
team concludes.
[Top]
Insider's
view into cancer may improve treatments –(Times of India Online-19/06/2001)
British researchers
said on Sunday they have developed a new technique that could improve
the accuracy and effectiveness of radiotherapy treatments for cancers
and reduce harmful side effects. It combines two widely used scanning
techniques, computed tomography (CT) and magnetic resonance imaging (MRI),
to create computer-generated images of cancerous tumours. The technique
will initially be used for radiotherapy for prostate cancer patients,
but it could be helpful in treating other tumours, particularly in the
pelvis, head and neck.
The technique combines
the best of CT, which gives a good location of a tumour in the body, and
MRI, which shows plenty of detail. It fixes points on the CT image and
relates them exactly to the same points on the MRI to produce enhanced
images. Together they will give the exact size, shape and location of
the tumour and allow doctors to concentrate radiation treatment more accurately
and maximise the dose to the tumour while avoiding hitting healthy cells
or tissue. Up to half of all cancer patients will undergo radiotherapy
sometime during their treatment, so the technique could have wide applications.
Scientists hope to use it for brachytherapy, a treatment for prostate
cancer that involves inserting very fine radioactive needles in the walnut-size
gland, sometime next year.
Prostate cancer is
the second commonest cancer in men. Surgery and radiotherapy, beams of
ionising radiation or radioactive seeds, are used to treat the illness
that afflicts mainly older men. Because the gland is located so close
to the rectum and bladder, the radiotherapy must be very precise so it
does not damage the other organs. But it must cover the entire tumour
and the pathways through which it can spread to other parts of the body.
[Top]
Men
who eat soy and tomatoes reduce their risk of prostate cancer, study shows-(Cancer
Info-09/06/2001)
Men at risk of prostate
cancer might want to include more tofu and soy milk in their diets. Although
the study was conducted with mice, and results must be replicated with
humans, researchers found that a chemical found in soy slowed prostate
cancer growth in mice and caused prostate cancer cells to die.
The soy chemical found
to reduce prostate cancer in mice is called genistein, one of two compounds
in soy that belong to a family of chemicals known as isoflavones. Isoflavones
are phytoestrogens, plant based chemicals that mimic the effects of estrogen
in the body. The researchers have identified the mechanisms by which genistein
may work in prostate cancer, and it's consistent with other studies of
soy. However, genistein must be tested in patients with prostate cancer
to be certain of its effectiveness. Researchers theorize that the prevalence
of soy in Asian diets may be one reason why men in Asia have a lower rate
of prostate cancer than men in the United States.
Prostate cancer is
the most common cancer among American men. The American Cancer Society
estimates that there will be 334,500 new cases of prostate cancer in the
United States this year. Prostate cancer is expected to kill over 40,000
American men this year.
The scientists tested
a commercially made extract of genistein on mice bred to develop prostate
cancer and on metastatic prostate cancer cell lines. In mice, genistein
reduced prostate cancer tumor growth. In the tissue culture, genistein
increased the production of p21, a gene that regulates cell growth, and
it reduced the production of vascular endothelial growth factor, a protein
that helps cancer grow. These factors caused cancer cells to die. The
researchers are now evaluating the effects of genistein in men who have
been diagnosed with slow growing prostate cancer.
The cancer center
intends to enroll 70 men in a pilot study to see if genistein lowers levels
of prostate specific antigen, a tumor marker for prostate cancer. Men
who have chosen not to receive treatment for prostate cancer or who have
undergone treatment and whose prostate specific antigen levels are rising
slowly are eligible to volunteer for the trial. Results will be known
in a year.
It is unlikely genistein
would become a stand-alone treatment for prostate cancer, but it could
be used in conjunction with conventional therapy or as a preventive drug,
if it indeed lowers prostate specific antigen.
Other components in
foods have been found to reduce prostate cancer. Studies now show that
an all-natural supplement of lycopene, the chemical that makes tomatoes
red, may help prevent and treat prostate cancer. A study of 30 men with
prostate cancer, reported in 1999 at the annual meeting of the American
Association for Cancer Research, showed that those patients who took lycopene
supplements had smaller tumors, which were more likely to be confined
to the prostate. The tumors in patients who consumed the lycopene showed
signs of regression and decreased malignancy. Like many antioxidants,
lycopene absorbs oxygen-free radicals that can damage DNA, and is believed
to be responsible for many types of cancer. The findings suggest that
lycopene may not only help prevent cancer, but may also be useful in treating
men who are already diagnosed with prostate cancer.
[Top]
Experimental
Abbott drug halts spread of prostate cancer-(Cancer Info-06/06/2001)
Abbott Laboratories'
experimental drug to treat prostate cancer has been shown to delay the
progression of the disease in patients who begin to fail current commonly
used treatments, according to a new study. The study of 244 patients on
ABT-627 is important for men with late-stage prostate cancer because they
eventually stop responding to widely used hormonal therapies such as Lupron,
sold by Abbott affiliate TAP Pharmaceutical Products Inc.
ABT-627, also known
as atrasentan, comes in pill form and is taken once daily. Hormonal therapies
like Lupron are injected once a month or every three or four months. Data
released Monday at the American Urological Association meeting in Anaheim
show that more than half of the patients who took a daily 10 milligram
dose of ABT-627 had no progression of the disease after 196 days on the
drug. ABT-627 is entering final-stage clinical trials.
Abbott doesn't expect
to seek Food and Drug Administration approval of the drug until the end
of 2003, with possible approval by mid-2004, the company said. Yet the
drug is gaining excitement at Abbott, which is hoping ABT-627 could be
used to treat other cancers.
[Top]
Prostate
cancer drugs cause significant bone loss-(Cancer Info-06/06/2001)
Men who receive hormone-suppressing
drugs to prevent the spread of their prostate cancer should be monitored
for bone loss, researchers advise. While prostate cancer drugs that lower
a man's testosterone levels are known to decrease their bone mass, this
side effect has garnered little concern in the past because hormonal therapy
was reserved for men with advanced cancer. But a growing number of doctors
are using testosterone-lowering drugs in the earlier stages of prostate
cancer in order to prevent its spread. This makes the specter of osteoporosis
as a side effect of treatment a greater health threat.
The study of 60 men
treated for prostate cancer gives weight to this concern. They found that
the 19 patients who received testosterone-lowering drugs called gonadotropin-releasing
hormone agonists (GnRH-a) had bone mineral densities that were up to 17%
lower than those of patients not given the drugs. They also showed signs
that their bones were thinning at a significantly higher rate. According
to the report in the June issue of the Journal of Clinical Endocrinology
and Metabolism, GnRH-a therapy can result in a decade's worth of normal
bone loss within the first year of treatment and the longer the men were
on the drugs, the greater the drop in bone mass.
The patients had been
on GnRH-a therapy for a little more than three years, on average, and
all were receiving the drugs to prevent their cancer from spreading. Prostate
tumor cells use testosterone to grow. Because the therapy lowers testosterone,
it helps keep tumor cells in check. Traditionally, the therapy has been
used for cancer that has spread beyond the prostate gland and out of reach
of surgical removal. More recently, however, doctors have begun using
the drugs in conjunction with surgery to prevent the disease from spreading.
But because lowering men's testosterone levels triggers a sort of male
menopause, a growing number of patients may face the risk of osteoporosis
and bone fractures. Patients should be counseled on the importance of
calcium, vitamin D and exercise in maintaining bone mass, and some may
need medications that help prevent bone loss.
[Top]
Oily
fishes reduce chances of prostate cancer-(Times of India Online-02/06/2001)
Eating even moderate
amounts of oily fish such as mackerel, salmon and sardines might reduce
the risk of prostate cancer in half, new research suggests. Omega-3 fatty
acids, plentiful in dark, oily fish, are known to fight heart diseases.
They also have shown promise in protecting against cancers of colon, rectum
and ovary. Previous studies have shown fatty fish oils can impede the
growth of prostate cancer cells in laboratory dishes and in animals. In
another study, prostate cancer was found less frequently in men who had
high levels of fatty acids in their blood.
Now, a new study,
published this week in The Lancet medical journal, found that Swedish
men who ate greasy fish only occasionally or not at all were twice as
likely to develop prostate cancer as those who made it a moderate or large
part of their diet.
However, scientists
pointed out that there could be other dietary patterns that go along with
eating very little fish that could be at work. People who seldom or never
eat fish tend to substitute with more red meat and scientists believe
animal fat butter, cream, beef, pork and processed meats may encourage
prostate cancer. Also, Swedish men eat a lot of oily fish, so there weren't
many in the group who ate very little of it. That means that although
the study involved thousands of men, the effect seen was driven by a small
number of men with unusual eating habits. With such a small sample, it
is difficult to rule out the possibility that it was not the fish itself,
but something else about the men who were not big fish eaters.
Prostate cancer strikes
about 21 out of every 100,000 men worldwide, according to the World Health
Organisation. It is most common in North America and northwestern Europe.
The study involved 6,272 men followed for about 30 years. During the study,
466 of them were diagnosed with prostate cancer, on average when they
were 76 years old.
The link between the
fatty fish and a reduced frequency of prostate cancer was even stronger
after the results were adjusted to account for the influence of other
eating habits, a genetic predisposition to prostate cancer and smoking,
drinking and exercise habits, the study said. It was also found that the
fattier the fish it is, the less you have to eat to get the same benefit.
Sardines have the most omega-3 oil in them, while the concentration in
tuna is quite a lot less, Wolk said, adding that it doesn't matter if
the fish is canned.
[Top]
High
boron intake may cut prostate cancer risk-(Times of India Online-08/04/2001)
A new study suggests
that men who consume high levels of boron-an element found in fruits and
nuts-reduce their risk of prostate cancer. The study compared the diets
of 76 men diagnosed with prostate cancer to the diets of 7,751 healthy
males. All of the men completed 1-day dietary recall surveys.
When the men were
divided into four groups, or quartiles, based on their consumption of
boron, the men in the highest-consumption group had a 64 per cent lower
risk of developing prostate cancer. It appears that the more boron-rich
foods and beverages consumed, the greater the risk reduction. Men in the
second quartile had a 35 per cent reduction in risk, while those in the
third quartile reduced their risk by 24 per cent.
The protective effect
of boron was independent of other risk factors such as age, smoking, obesity
and race. However, there was no protection associated with boron for other
cancers.
3.5 servings of boron-rich
fruits and one serving of nuts a day would put men in the top quartile.
One serving of nuts is the equivalent of a handful of peanuts or almonds.
Other good boron sources include grapes, dried fruits, avocados, red wine
or grape juice. The study results are based on a small number of prostate
cancer cases, so the finding will have to be confirmed in a larger study.
[Top]
New
hope for prostate cancer patients who have failed radiation therapy-(Cancer
Info-04/04/2001)
An innovative technology
is offering men whose prostate cancer recurs after radiation therapy new
hope. SeedNet, a freezing technique used to destroy the diseased prostate
gland without damaging the surrounding healthy tissue, is the only option
to improve long-term survival in men who experience a recurrence of the
disease. The system gives the physician much greater control in destroying
the diseased gland with less risk and pain to the patient.
Prostate cancer is
the second leading cancer killer of men in the United States. Each year,
40 percent of the 180,000 men diagnosed with prostate cancer undergo radiation
therapy. In nearly 22,000 men, radiation fails and the cancer returns.
The SeedNet technology
uses 12 tiny needles that are inserted through a template into the prostate
gland, directly through the skin of the perineum, avoiding the use of
cumbersome insertion kits. The needles use supercold argon gas to generate
patented IceSeeds that combine to form a precisely contoured iceball to
freeze the diseased tissue and destroy the gland without harming the surrounding
healthy tissue. The physician watches the placement of the needles and
the freezing process through transrectal ultrasound imaging technology.
The unique procedure evenly distributes the cancer-killing seeds safely
and effectively with minimal invasiveness, making it the best treatment
option for patients who cannot or prefer not to undergo radical prostatectomy.
Unlike surgical removal
of the prostate, which requires a two to three day hospital stay, the
SeedNet system allows the patient to return home the same day. The procedure
is performed in a hospital under anesthesia. Recovery time is quick and
the patient is able to resume normal activities soon after the procedure.
There is little risk of incontinence or fistulas developing, though as
with other prostate treatments, there is the risk of impotence, but figures
for cryosurgery are not yet conclusive. The patient returns to the doctor
for a PSA reading after three months and is then screened on a biannual
basis.
The SeedNet system
is based on technology developed by the Israeli military to cool the infrared
devices that guide missiles. The proprietary device uses the brachytherapy
insertion template, which is already commonly used by urologists for treating
prostate cancer with radiation.
[Top]
Natural
substances in fruits and vegetables may be potential treatment for prostate
cancer-(cancer Info-28/03/2001)
Quercetin, a natural
substance found in apples, onions, tea and red wine, may be a potentially
novel approach for preventing and treating prostate cancer, according
to a laboratory research study. Laboratory results showed quercetin blocks
the androgen (hormone) activity in androgen-responsive human prostate
cancer cell lines.
By blocking the androgen
activity, the growth of prostate cancer cells can be prevented or stopped.
The study suggests quercetin may be a potential non-hormonal approach
to accomplishing that goal.
Prostate cancer is
the second leading cause of cancer death in men in the United States.
It annually claims about 31,500 men, accounting for about 11 percent of
male cancer related deaths. The findings may lead to another treatment
option for the nearly 200,000 men diagnosed with prostate cancer annually
in the United States. It also may mean that eventually some men may not
have to undergo castration, the current, commonly used treatment for advanced
prostate cancer. However, more research is required to determine whether
the preliminary laboratory findings about quercetin translate into actual
benefit for men either at risk or diagnosed with prostate cancer.
Quercetin is an abundant,
naturally occurring flavonoid compound. In addition to apples, onions,
black and green tea, and red wine, the compound is found in green leafy
vegetables, beans and citrus fruits. Quercetin has been studied scientifically
for the past 30 years. It’s documented as safe and having relatively low
toxicity. The compound is currently used in therapeutic treatments for
allergic conditions such as asthma, hay fever, eczema and hives. It’s
also used clinically to treat several inflammatory conditions, including
gout, pancreatitis and prostatitis.
This study is the
first research indicating quercetin has significant activity against the
androgen receptor in the human prostate cancer cell lines. Androgens are
male hormones, the most common being testosterone. Androgens also are
involved in the development, progression and growth of prostate cancer.
The biological effects of androgens in the prostate are mediated by the
androgen receptor. An activated androgen receptor can turn on or off critical
genes, which affect the biology and pathology of the prostate. Laboratory
data showed that androgen receptor expression was inhibited by quercetin
and the rate of response was dose-dependent. The study also delineated
the mechanism by which quercetin reduced the androgen receptor.
[Top]
Quality
of life varies after prostate cancer-(Times of India Online)
When it comes to prostate
cancer treatment, men tend to report similar changes in their quality
of life regardless of whether they opt for surgical removal of the prostate
or radiation treatment. However, the side effects do differ between the
two groups. A man is more likely to experience incontinence or impotence
after surgery, and radiation treatment is associated with bowel problems.
The investigators
also found that men who had their prostate cancer diagnosed early faired
similarly in terms of quality of life compared with men who were diagnosed
during more advanced stages of the disease. It cannot, therefore be conclude
that one treatment is preferable over the other. Each results in different
consequences, and it is important that patients have easy access to unbiased
information about possible side effects of the treatments.
In the study, the
researchers followed 278 men who underwent prostate cancer treatment.
The men filled out a questionnaire that assessed various aspects of their
health at 6 and 12 months after treatment. About 39% to 49% of men who
had surgery experienced urinary incontinence, and 80% to 91% had erectile
dysfunction. In men who had radiation treatment, 6% to 7% had urinary
incontinence and 41% to 55% had erectile dysfunction, according to the
report.
Bowel problems affected
30% to 35% of the men who had radiation therapy compared with 6% to 7%
of patients who had their prostates surgically removed, the findings indicate.
As for overall quality
of life, patients who had radiation rated their physical health one year
after treatment as 72/100, while surgery patients rated their health as
89/100. When it came to emotional health, radiation patients rated this
as 83/100 one year later while surgery patients said their emotional health
was 93/100.
Some side effects
may be more of a concern to some patients than others, the authors note.
Thus, patients need to be completely aware of the potential risks so that
they can make an informed decision about treatment, the researchers explain.
On an individual level, patients should be made fully aware of the potential
benefits and adverse consequences of the available therapies for early
prostate cancer, the study concludes.
[Top]
Computerised
treatment may help prostate cancer-(Times of India-22/02/2001)
Using computers to
help plan brachytherapy-the placement of radioactive seeds near a prostate
tumour-can reduce damage to surrounding healthy tissue and improve control
of the cancer. The computerized system generates a treatment plan in 5-15
minutes which allows treatment planning to occur immediately before the
procedure, using accurate imaging data regarding the shape of the patient’s
prostate instead of data that may be several weeks old.
More seeds are placed
in the prostate instead of in surrounding tissue. It also avoids placing
seeds in the urethra and rectum, errors that can cause "hot spots",
leading to incontinence, a common side effect of brachytherapy.
[Top]
Saw
Palmetto May Fight Prostate Cancer -(Cancer Info-10/12/2000)
Extract from the Saw
Palmetto berry (SPBE), a commonly used herbal supplement taken by men
with enlarged prostates, may also have anti-cancer properties, researchers
announced at The American Society for Cell Biology meeting here.
The research team
analyzed the effects of SPBE on cancer cells. To accomplish this, they
exposed prostate cancer cells and a generic cancer cell line to various
concentrations of berry extract. The cancer cell growth in laboratory
cell cultures was then monitored. About one-fifth the amount of berry
extract was needed to decrease the cell growth of the prostate cancer
cells compared to the amount needed to slow down the growth of the generic
cancer cells. This demonstrates that the effect of the berry extract is
fairly specific in its impact on prostate cancer cells.
In a second study,
the researchers monitored the production of COX-2 protein by the cancer
cells, and found that it was also decreased in both types of cancer cells
following berry extract exposure. So far eight different chemicals in
the extract have been identified. Once more is known about each component,
it will be possible to identify which chemical has the most potent effect
on prostate cancer cells and develop that into a treatment.
[Top]
Popular
Herbal Compound Causes Prostate Cancer Cells to Die, Study Finds- (Cancer
Info- 09/10/2000)
Researchers are finally
discovering what herbalists have known for decades that a Chinese herbal
mixture taken by a growing number of prostate cancer patients appears
to work in part by inducing tumor cells to die.
Researchers from Columbia
University in New York and Henry Mondor Hospital in France measured the
effects of PC-SPES, a compound consisting of eight herbs, on three different
human prostate cancer cell lines, on human tumors implanted in mice and
in a group of 69 men with prostate cancer. Since it first became commercially
available in 1996, scientists have been studying PC-SPES, which as an
herbal remedy is not regulated by the Food and Drug Administration. While
there is a broad consensus that the mixture appears to mimic the actions
of estrogens-and therefore counters the impact of tumor-fueling male hormones--investigators
haven't been able to determine exactly how PC-SPES works against prostate
cancer.
In this study, scientists
took a three-pronged approach. First, they tested the actions of the compound
on human prostate cancer cell lines that included both hormone-sensitive
and resistant. After exposure to PC-SPES for five days, the scientists
saw that it caused cell death, called apoptosis, in all three cell lines.
Next, they gave PC-SPES
to mice injected with hormone-resistant human prostate cancer cells. They
found that PC-SPES did not suppress tumor growth when injected into mice
one week after tumor injection. But if PC-SPES therapy began the same
day as tumor injection, it led to smaller tumors, compared to those in
animals not receiving PC-SPES. Though this difference did not reach statistical
significance, the tumor shrinkage, combined with shrinkage of the testes
and prostates of treated mice, led to the conclusion that PC-SPES has
estrogen-like effects.
The third facet of
the study examined the effects of PC-SPES in men with prostate cancer.
The 69 men were split into three groups: 43 men who had received prior
therapy and were considered to have hormone-sensitive disease; 22 men
who had received prior hormone therapy but were experiencing a recurrence
and classified as having hormone-resistant cancer; and four men who were
receiving PC-SPES as primary therapy. All patients took capsules of 320
milligrams of PC-SPES orally three times a day. Of the four patients receiving
PC-SPES as primary therapy, two had a decline in levels of the tumor marker
prostate-specific antigen (PSA) of greater than 50 percent after two months.
Of the 22 men with hormone-resistant disease, PSA decreased in 90 percent
after two months, and remained lower at six months in 74 percent. Of the
43 men considered to have hormone-sensitive disease, decreased PSA was
observed in 82 percent at two months, 78 percent at six months and 82
percent at 12 months. In terms of side effects, 42 percent of all the
men reported swollen, tender breasts, 7 percent had hot flashes and 2
percent had clots in their veins.
It was concluded
that "the observation that this agent has a clinical effect on patients
with hormone-resistant prostate cancer suggests that estrogen-like activity
is not its sole mechanism of action."
The efficacy and toxicity
of PC-SPES should be a call to action for elected officials to demand
testing of agents, such as these, that by any other definition are truly
pharmaceuticals said one researcher. But he cautioned that strokes and
heart attacks attributable to PC-SPES could occur as the popularity of
this untested and unregulated compound grows.
[Top]
Researchers
Criticize Prostate Screening Tests-(Cancer Info-04/09/2000)
Robert Dole, Arnold
Palmer and Harry Belafonte have all gone on television to urge men over
50 to get tested for prostate cancer. But the widespread screening advocated
by the American Urologic Association and the American Cancer Society may
lead to more harm than good, two British researchers argue in a paper
in the current Lancet Oncology. Until a study proves that screening leads
to a drop in prostate cancer deaths, ``the ethics of subjecting symptom-free
men to screening tests is questionable,'' wrote David Neal, a professor
at the School of Surgical Sciences at the University of Newcastle upon
Tyne, and Jenny Donovan, a researcher at the University of Bristol's Department
of Social Medicine.
Theirs is the latest salvo in a debate that pits urologists and radiation
oncologists against some family physicians and preventive-medicine experts,
who say the screening catches too many dormant cancers that would never
have become lethal, leading to unnecessary treatment with side effects
that damage quality of life. Many men become impotent and incontinent.
Advocates on the other
side are equally passionate. Dr. Robert Smith, an epidemiologist at the
American Cancer Society, said physicians could ``wait forever for the
perfect gold-standard data.'' But he called that a conservative approach
that ignores signs that screening may be saving lives. For example, he
said, there has been an 11 percent drop in mortality among black men since
1993 and a 16 percent drop among white men since 1991. And in one Austrian
county where screening was introduced, mortality rates fell 42 percent,
he said.
The incidence of prostate cancer spiked after screening was introduced
around 1989, and has now fallen below its 1992 peak. In the paper, it
has been argued that while screening that caught cancers at a treatable
stage could have caused drops in mortality, they also could simply reflect
that more non-aggressive cancers were caught.
Smith of the American Cancer Society said he is confident that a cancer-screening
trial now being run by the National Cancer Institute will validate screening.
But in the meantime, he said, it is important that men receive complete
information about the risks of treatment so they can make informed decisions.
[Top]
Update
on Prostate Cancer-(Times of India-22/08/2000)
Researchers who reviewed
records of 2800 men who had surgery for prostate cancer found that 29%
had a recurrence and 6% had a recurrence after 5 years. Cancer progression
was followed through a blood test for prostate specific antigen and physical
examinations.
The risk is greatest
during the first two years. Patients who had prostate surgery should get
follow-up screening for the rest of their lives, so that if the cancer
does appear, medical intervention can be made.
[Top]
Drug
Hikes Rate Of Death In Cancer Cells Only-(Cancer Info-02/05/00)
Columbia Presbyterian researchers have shown that a new drug may be a
viable treatment option for slowing tumor growth in men with advanced
prostate cancer. The study is the first of its kind to show a significant
effect of a new class of drugs that may stabilize progressive, recurrent
disease in patients with advanced prostate cancer.
Evidence indicates
that the drug, Exisulind, increases the rate of programmed cell death
in cancer cells without damaging normal cells. Exisulind is from a new
class of compounds called selective apoptotic anti-neoplastic drugs (SAANDs).
SAANDs inhibit cyclic GMP phosphodiesterase and selectively induce apoptosis
(programmed cell death) in abnormally growing precancerous and cancerous
cells.
Because SAANDs do
not induce apoptosis in normal cells, they do not produce most of the
adverse reactions or serious side effects normally associated with chemotherapeutic
agents used to treat cancer.
[Top]
Chemoprevention
for Prostate Cancer Looks to Drugs, Antioxidants-(Cancer Info-28/03/00)
As the average age
of Americans rises, preventing prostate cancer is becoming a vital area
of research, and the focus is turning from general recommendations about
diet, such as eating less fat and more fruits and vegetables, to exploring
specific agents, including vitamins and drugs. About 30 percent of men
between ages 30 and 39 have at least some cancer cells in their prostate,
and that number rises to 50 percent for men in their fifties, said William
G. Nelson, M.D., a medical oncologist at Johns Hopkins University Hospital
in Baltimore. "It's a staggering thought, even as the population gets
older on average," he added. To prevent these indolent cancers from turning
aggressive, scientists are exploring the effects of a variety of substances,
ranging from chemotherapeutic drugs used for other cancers to substances
found in foods. At the Advances in Human Breast and Prostate Cancer conference
here recently, researchers discussed this burgeoning area of research
called chemoprevention.
One of the more promising
possible chemopreventive agents comes from a class of drugs called selective
estrogen receptor modulators (SERMs). These are thought to act by plugging
into certain proteins on the surface of cells, thereby preventing estrogen
from binding to those same sites and promoting cell growth. Blake Lee
Neubauer, Ph.D., is one researcher looking at a specific SERM with the
minimalist name LY353381-HCI to explore its potential for preventing the
growth and spread of prostate cancer. It's already being tested in phase
II randomized trials for women with breast cancer, and considering the
hormone-based growth of prostate cancer, it's being investigated for use
in men with that disease as well.
And Don't Forget Antioxidants
Also of potential
relevance to the prevention of prostate cancer is a collection of agents
ranging from a substance found in tomatoes, to vitamins. Among the major
cancers, prostate cancer is the least understood from an epidemiological
point of view, observed Ronald Ross, M.D., an epidemiologist from the
University of Southern California in Los Angeles, "which makes it difficult
to target prevention pathways."
Some substances that
merit future research in Ross's view are antioxidants, androgen suppressors
and vitamin D. "Each of the pathways [these substances affect] has several
biological goals in common," he said, which are decreasing cellular proliferation,
increasing cellular differentiation (return to a normal mature form),
increasing apoptosis (programmed cell death) and decreasing mutations.
Based on a 1993 study out of the California-based Kaiser-Permanente group,
there's evidence supporting vitamin D as a chemopreventive agent, Ross
said. But scientists are still working out how to prevent hypercalcemia,
a common side effect of taking too much of the vitamin. The antioxidants
include selenium, lycopenes and vitamin E. Antioxidants neutralize free
radicals, which can cause potentially cancer-stimulating DNA mutations.
[Top]
Cancer
docs OK controversial prostate therapy- (Cancer Info-17/03/00) *
A
controversial treatment for prostate cancer in which radioactive seeds
are implanted in the prostate to destroy the tumor received support Friday
from doctors writing therapy guidelines for the prestigious 17-hospital
National Comprehensive Cancer Network (NCCN) meeting in Ft. Lauderdale,
Fla. Known as brachytherapy, the procedure has been performed for years
by researchers across the country, but previous treatment guidelines for
prostate cancer left the procedure out.
[Top]
Many prostate cancer
patients use alternative medicine (Reuters Health-15/12/99) Source: Cancer
1999;86:2642-2648.
A survey of men with prostate cancer found
that 43% of them reported using
some form of alternative medicine, University
of Virginia scientists report in the December 15th issue of Cancer. But
almost 3 out of 4 of these men do not tell their doctors that they are
using alternative therapies, which is a problem because it may interfere
with traditional therapy.
``It was surprising how prevalent the use
was,'' study author Dr. Dan Theodorescu said in an interview with Reuters
Health. He explained that it is important for patients to tell their physician
that they are using herbal therapies because they can mislead the doctor
as to how well conventional cancer medications are working.
Speaking with Reuters Health, Theodorescu
stressed that some herbal medications can affect levels of things physicians
use to monitor the progression of prostate cancer, such as prostate specific
antigen (PSA), testosterone, and estrogen.
``You have got to tell your doctor, and the
doctor has to ask,'' Theodorescu said, adding that ``a lot of these agents
have an effect on cancer.'' He warned, ``Some of these (alternative therapies)
have side effects, so (the patients) may harm themselves. Or they may
blame side effects on the drug they're taking when in fact the herbal
therapy is causing it.''
``I wouldn't say any of these (alternative
remedies) should be used in patients outside of clinical trials,'' Theodorescu
said. ``We're far away from integrating them into conventional medicines...
but (we) on the clinical front are pretty excited about some of these
things.'' He added, ``We will be seeing some pretty interesting drugs
in the next 5 to 10 years stemming from these herbal remedies.''
The authors note that 42% of the US population
reports using alternative medicines, and 7% - 64% of cancer patients report
using them. According to the American Cancer Society, prostate cancer
is the most common cancer among men, and the second most deadly after
lung cancer.
[Top]
Gene
therapy to be tested on prostate cancers (Medivision- November, 99)
Three top US medical facilities are starting
a clinical trial of a new form of gene therapy for men with prostate cancers
that are hard to treat. The Cleveland Clinic, the University of California,
and the Walter Reed Army Medical Centre in Washington is experimenting
with a material called leuvectin, made up of DNA. Early data shows that
it is safe and has a significant anti-cancer effect.
[Top]
Dr
V Srinivas: The newest procedures for cancer of the prostate - (Medivision-September,
99)
Dr V Srinivas, Consulatnt Urologic Oncologist
at Hinduja Hospital, in his book Urological Oncology gives an overview
about what is available in the west and what can be done in India.
[Top]
|
