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BLOOD CANCER
Wonder
drug helping Carlos-(ET-18/12/2003)
Carlos Valencia is
playing basketball and hopes to hold off on a marrow transplant a while
so he can watch his beloved UA Wildcats. The drug that has suppressed
Carlos Valencia's leukemia can't help him with his upcoming English exam.
Gleevec, which Carlos takes at morning and evening, has reduced his leukemia
dramatically, doctors say. Tucson teen's leukemia is at bay, lets him
wait a little for transplant Carlos Valencia is trying to persuade his
doctors to put off his bone-marrow transplant - needed to save his life,
mind you - until spring, so he won't miss any of the University of Arizona
basketball games. But he may actually get his crazy wish, now that a new
"miracle drug" is working wonders on this well-known and much-loved Tucson
teen, stricken for the second time with life-threatening leukemia, a cancer
of the blood and bone marrow. The drug - Gleevec - may give Carlos, now
15, not only the basketball season he wants so much, but also vital extra
time to search for elusive matching bone marrow to make the transplant
work.
Approved for use
in the United States only for the past two years, Gleevec is perhaps the
closest thing to a "magic bullet" for cancer ever discovered. It targets
chronic myelogenous leukemia (CML) - the type Carlos has been fighting
for three years - and is already cutting into the disease's 50 percent
mortality rate. Fully 80 percent of CML victims are achieving significant
remissions on Gleevec, studies show. Before Gleevec, only 14 percent responded
that well when taking the standard CML drug, interferon. Gleevec is the
reason actor Ryan O'Neal, 62, is back in the movies and starring in a
new television drama series, after being diagnosed with CML two years
ago. O'Neal started taking the drug last year and is now in complete remission.
As is Carlos today, after his leukemia returned three months ago, following
a failed cord-blood transplant 2 1/2 years earlier. Carlos started taking
Gleevec in late September. "He is in molecular remission - that is the
highest degree of remission we can achieve," said Dr. Michael Graham,
director of pediatric bone marrow transplantation at University Medical
Center. "The most sensitive test we can perform has come back negative.
We can detect no leukemic cells in Carlos now. We would have never seen
this kind of response without Gleevec."
Gleevec was not available
for Carlos during his first battle against leukemia, when his charismatic
presence triggered the largest bone marrow donor drives ever held in Tucson.
He is credited with singlehandedly bringing thousands of much-needed Hispanics
into the national bone-marrow registry as potential donors. Developed
during the past decade, Gleevec works in an entirely different way from
standard, toxic cancer chemotherapy drugs. It directly blocks the abnormal
protein that signals the overproduction of diseased white blood cells
causing CML. As a result, the drug has few side effects and is easily
tolerated by patients. Carlos feels some nausea for about 20 minutes after
he takes his pills, in the morning and evening. "My energy is good. I've
gained about 15 pounds, I'm playing basketball," said Carlos, a Salpointe
Catholic High sophomore in the middle of exams. Flashing a smile, his
now-long legs stretched out in front of him, he said, "There are no limits
on me now." As his father, Ford Valencia, puts it, "His whole appearance
is great - he's got his glow back. This is a wonder drug."
Most crucially for
Carlos, Gleevec has so effectively fought off his leukemia that his doctors
no longer feel the urgency they did a few months ago to get him transplanted
as soon as possible. Once aiming for a November transplant, Graham now
says it may happen in February or even later. "This is giving us a much
larger window to look for a match for him, and I'm confident we'll be
able to find something," Graham said. "We now have the time to look worldwide,
at other ethnic groups that we think may provide a better match for him.
"With how well he's doing on Gleevec, it's safe to postpone it while we
figure out the best option for him."
It was the cruelest
of ironies that despite the thousands of people who became potential bone-marrow
donors at drives for Carlos, no bone-marrow match was ever found for him.
Instead, he underwent a transplant using donated umbilical-cord blood,
a more immature form of blood stem cells that do not require as close
a match as actual bone marrow. But this time around, with Gleevec reducing
his leukemic cells to apparently nil, Carlos will have a flying start
at a successful transplant. "At his level of remission, there is a million-fold
reduction in his leukemia burden," said Dr. Brian Druker, head of leukemia
research at the Oregon Health & Science University Cancer Institute, who
developed Gleevec. "The best news is we have looked at patients with even
a thousand-fold reduction, and nobody has relapsed." There is even talk
that Gleevec might prove a cure for CML. But with patients on it only
a few years so far, it is too early to know if remissions will last for
decades. "We're not counting it out," said Druker. "But right now, I think
the combination of Gleevec and a bone-marrow transplant is the ticket
for a cure."
Hearing Gleevec success
stories like Carlos' gives Druker "an unbelievable feeling," he said.
"You go to medical school hoping to help people, of course, and any physician
takes great pride every day in doing that, and in improving the quality
of people's lives," he said. "But for me, this goes beyond that. It's
absolutely a dream come true. It's so amazing to hear that someone, the
young man you are telling me about, is doing so well. I'll never get tired
of hearing that." As he awaits his transplant, Carlos is maneuvering to
make sure he misses not one UA basketball game, no matter when Graham
decides to do it. Best case for Carlos is waiting until March, when the
UA men's basketball team will likely reach the NCAA tournament and games
will broadcast on network TV, which UMC gets in patient rooms. But if
it happens earlier, when most regular season games are on cable stations,
that would be a problem, since UMC TV's don't get those stations. "Right
now, he's working on getting all the cable stations changed here at the
hospital, in case that happens," said Graham, laughing. "But there's a
chance we could put it off till March."
[Back]
Chemo-Stem
Cell Combo Fights Bone Cancer-(AP-24/12/2003)
An unusually intensive
assault on the cancer multiple myeloma - using two rounds of high-dose
chemotherapy followed each time by a stem cell transplant - appears to
double patients' long-term chances of survival, a study found. Although
the approach is not a cure, doctors say the results are encouraging for
victims of this usually lethal cancer of the bone marrow. The researchers
found that after seven years, 42 percent of patients who got the double
treatment were still alive, compared with 21 percent of those who received
the standard single round of chemo plus a transplant. The head of a U.S.
marrow transplant program said the French study is another important development
in what has been an exciting year for multiple myeloma research, including
federal approval in May of the drug Velcade, which targets one of the
underlying defects that make this cancer grow. If such developments continue,
"I'm very optimistic that we will be thinking of this as a curable disease
within my professional career," said Dr. Edward Stadtmauer of the University
of Pennsylvania's Abramson Cancer Center.
A transplant allows
a higher dose of chemotherapy, because it puts the patient's stem cells
back into the body to replace those killed by the treatment. Stem cells
are a crucial component of bone marrow, which produces blood cells. The
study, led by Dr. Michel Attal of Purpan Hospital in Toulouse and published
in New England Journal of Medicine, looked at 199 patients who got two
rounds of treatment, and 200 who got a single set. In addition to increasing
life span, the second round of treatment doubled the chance of surviving
seven years without a recurrence of cancer (20 percent versus 10 percent).
The difference was most striking for people who had not had a good response
to the first transplant. Only 11 percent of those patients lived seven
years without a second transplant. With a second transplant, 43 percent
survived that long. Stem-cell transplants are expensive - a single round
can cost $150,000, about triple the cost of standard chemotherapy - and
dangerous: Five people in each group died from the transplant itself.
"It may be that patients
who are not doing well after a first transplant should automatically go
in for a second transplant. That may be the most important lesson to get
from that study," said Len Lichtenfeld, deputy chief medical officer American
Cancer Society. Multiple myeloma is described both as a bone cancer and
a blood cancer. It affects the plasma cells that make infection-fighting
antibodies. Instead of making antibodies against a wide variety of diseases,
the cells begin overproducing one and making too little of others. That
leaves patients anemic, open to infections and susceptible to bleeding.
Bones become painful and brittle. Other proteins interfere with kidney
function. A half-century ago, diagnosis meant almost certain and swift
death. Now, treatment can help many patients at least feel better for
a while and fight off infections, keeping them alive for years and even
decades.
[Back]
Gleevec
May Treat Other Leukemias, U.S. Study Shows-(Reuters-09/12/2003)
The cancer pill Gleevec,
which has produced striking results in patients with chronic myeloid leukemia,
may also help some patients with another form of leukemia which is hard
to treat, U.S. researchers reported. The drug, made by Swiss pharmaceutical
giant Novartis, helps starve tumors and is being tested against a range
of cancers. Research being presented at the American Society of Hematology
meeting in San Diego suggests it could help patients with acute lymphocytic
leukemia, also called ALL. A team at the University of Texas M. D. Anderson
Cancer Center paired Gleevec with high-dose chemotherapy in patients with
Philadelphia-positive ALL. Both CML and this type of ALL are caused by
a break in the so-called Philadelphia chromosome, named after the city
where the abnormality was discovered. Philadelphia-positive ALL accounts
for one-fifth of all cases of the leukemia, and is not easily cured. Only
12 percent to 28 percent of patients are still alive two years after diagnosis
even when they are treated with high doses of chemotherapy. Their chances
are better if they can get a bone marrow transplant from a closely matched
donor, but many patients do not have such a donor.
Dr. Deborah Thomas
and colleagues tested 24 patients with ALL, giving them Gleevec on top
of standard chemotherapy. Her team found that 23 of the patients went
into complete remission after a single three-week course of the pills.
The remissions have, so far, lasted up to 29 months after treatment. She
said larger studies are needed before it is clear how much Gleevec helps
these patients. The break in the Philadelphia chromosome results in the
production of an abnormal protein that causes overproduction of white
blood cells. Gleevec, sold as Glivec in Europe, blocks production of the
abnormal protein. The study is one of many that shows cancer therapy in
the future will be tailored to individual patients. Dozens of different
genetic defects can cause cancer and while some drugs work well in many
patients, they may not help others with the same form of cancer because
the underlying causes are different. ALL affects 3,800 people a year in
the United States and kills 1,400.
[Back]
Battling
Bone Marrow Diseases-(HealthDayNews-02/12/2003)
Aplastic anemia and
other related bone marrow diseases are relatively rare in the United States,
with about 40,000 new cases occurring each year. But research into the
diseases -- in which the body slows or stops the production of healthy
blood cells -- could help provide insight into more prevalent health problems,
such as heart disease, researchers say. To heighten awareness about the
conditions, Dec. 1-7 has been designated National Aplastic Anemia Awareness
Week. In addition, the National Institutes of Health recently awarded
a $4.5 million grant to spur additional research. The Cleveland Clinic
Foundation and Dr. Jaroslaw P. Maciejewski will use the money to create
a clinical research center dedicated to studying the bone marrow disorders.
The diseases have attracted federal support, in part, because they involve
damage to stem cells. And stem cells have attracted much research attention
due to their potential regenerative powers and ability to transform themselves
into a host of different cells. "There are scientific reasons to use rare
diseases in studies because they provide clues to treating more common
diseases," Maciejewski says of his research. "For example, bone marrow
is one of the best places to learn more about adult stem cells and their
regenerative properties."
There are many rare
bone marrow diseases, but the most common are aplastic anemia and myelodysplastic
syndromes, or MDS. The symptoms of these diseases tend to be extreme versions
of common medical problems, says Marilyn Baker, executive director of
the Aplastic Anemia & MDS International Foundation Inc. For example, a
victim might suffer from drastic bruising. "You open a pickle jar, and
the next day your hand is all bruised and swollen," she says. Other symptoms
could include hemorrhaging, extreme fatigue and chronic illness. "To one
of our patients, a cold would never go away and would turn into pneumonia,"
she says. Baker cautions that people suffering these symptoms do not necessarily
have bone marrow disease. They should ask their doctor for a simple blood
test that can determine whether they do.
Aplastic anemia occurs
when the bone marrow stops making enough blood cells, leaving the marrow
almost empty of blood-forming cells. About 1,000 new cases of the disease
appear each year in the United States. MDS happens when bone marrow begins
producing poorly functioning or immature blood cells. This disorder is
more common, with about 20,000 to 30,000 new cases each year. Doctors
have little idea what causes the diseases. "The strange thing about this
is there is no smoking gun," Maciejewski says. Some known potential causes
are exposure to radiation or toxins. "Sometimes cancer patients get our
disease as a result of their radiation treatment," Baker says. "Others
have been exposed to benzene, pesticides or insecticides."
As recently as 20
years ago, aplastic anemia was considered fatal, but advances in drug
therapies and bone marrow transplantation have allowed doctors to extend
the lives of victims by years. Remission rates now are 60 percent to 80
percent, up from about 30 percent a decade ago, Baker says. "It is still
often fatal," she says. "The president of our association has lived with
the disease for 13 years, but there are other patients I know who pass
away within six weeks." MDS sufferers are less fortunate. Remission rates
have not improved, although care has improved and the number of clinical
trial opportunities has also increased, Baker says.
Standard treatment
for bone marrow failure diseases involve bone marrow transplants and immunosuppressive
drug therapy. For patients who can't benefit from those treatments, experimental
options are available. Most sufferers must undergo regular blood transfusions.
The diseases are highly specialized, Maciejewski says, meaning that specific
treatment often depends on the individual sufferer. "If a patient is 10
years old, you wouldn't think twice before going to transplantation,"
he says. "If the patient is 70, you think three times before going there."
Because the diseases are so rare, and because complex decision-making
is necessary in choosing the right treatment, experts urge patients to
work with a hematologist who specializes in the specific bone marrow failure
disease in question. The $4.5 million grant is part of an overall NIH
effort to increase research into rare diseases. Other centers in the NIH
Rare Disease Research Network will study rare lung conditions, nervous
system disorders and rare genetic steroid disorders.
[Back]
Study
Links Psoriasis to Lymphoma Cancers-(Reuters-17/11/2003)
Psoriasis sufferers
may later develop lymphoma cancers at nearly three times the rate of people
who do not have the red and scaly skin condition, a study said. The reason
for the greater risk is not clear, said the report from the University
of Pennsylvania in Philadelphia. "Additional studies are necessary to
determine if the increased rate of lymphoma is related to psoriasis severity,
psoriasis treatment, or an interaction" of various factors, concluded
the report published in the November issue of the Archives of Dermatology.
Researchers said they reached the conclusion by looking at a random sample
from a British database that holds medical records for more than 8 million
patients. The records involved people of 65 or older who were treated
between 1988 and 1996. "Patients with psoriasis had an almost three-fold
increased rate of lymphoma compared with patients without psoriasis,"
the authors concluded. "Patients 65 years or older who had psoriasis developed
an additional 122 lymphomas per 100,000 patients annually."
Psoriasis is a common
skin disease characterized by patches of thickened, red and scaly skin,
usually on the torso or arms. It can be painful and disfiguring in some
cases and affects from 1 percent to 2 percent of the population. The article
said there had been previous research indicating psoriasis victims were
at higher risk for lymphoma but the degree of the risk had not been measured.
Lymphoma is a general word categorizing a variety of cancers of the lymphatic
system.
[Back]
SU5416
Demonstrates Activity in Refractory Acute Myeloid Leukemia-(ET-30/10/2003)
According to results
recently published in the journal Blood, the anti-angiogenesis agent SU5416
has demonstrated anti-cancer activity in the treatment of refractory acute
myeloid leukemia. Acute myeloid leukemia (AML) is a cancer of the bone
marrow and blood characterized by the rapid uncontrolled abnormal growth
of immature white blood cells (immune cells), which never develop into
functioning cells. Besides not being able to carry out the functions of
mature immune cells, AML cells may also crowd out normal blood cells in
the bone marrow and blood. AML is considered to be an aggressive cancer
and patients are often at a high risk of developing a cancer recurrence
following therapy, particularly if they are not able to undergo high doses
of therapy. However, chromosomal variables of AML cells as well as levels
of cancer cells in the blood further distinguish patients into being at
a high-risk, standard-risk or low-risk of developing a cancer recurrence
and treatment may be altered according to these stratifications. Patients
with AML that has stopped responding to standard therapies (refractory)
or elderly patients who are not able to tolerate standard chemotherapeutic
approaches are left with limited treatment options.
A new arena of cancer
research involves the inhibition of angiogenesis. Cancer cells require
food, oxygen and growth proteins in order to grow and spread. These essential
nutrients are transported to the cancer cells by blood vessels. Angiogenesis
is a complex process of creating new blood vessels necessary to transport
"food" to the cancer cells. Two key proteins that are necessary for the
process of angiogenesis are called matrix metalloproteinases (MMPs) and
vascular endothelial growth factor (VEGF). One of several properties of
VEGF includes the stimulation of endothelial cells (cells comprising the
innermost layer of blood vessels) to replicate and migrate from existing
blood vessels to the cancer. Endothelial cells secrete MMPs, which create
an opening in existing tissues surrounding the cancer, allowing the endothelial
cells to move near the cancer and form new blood vessels to "feed" the
cancer.
SU5416 is a novel
angiogenesis inhibitor still being evaluated in clinical trials. SU5416
produces its anti-angiogenic effects by binding to VEGF receptors on cancer
cells, which inhibits the action of VEGF. This halts the growth of new
blood vessels necessary to promote cancer cell growth. Moreover, VEGF
is expressed in a wide variety of tumor types and has been associated
with expression in immature cells in the bone marrow, called stromal cells,
which are associated with the cancer. A recent multi-institutional clinical
trial was recently conducted to evaluate SU5416 in the treatment of AML.
This trial involved 43 patients with either refractory AML or elderly
patients with AML who were unable to tolerate standard chemotherapy. Following
therapy with SU5416, 8 patients achieved an anti-cancer response. The
duration of response lasted between 1-5 months. Researchers noted that
patients with high levels of active VEGF had a significantly improved
rate of anti-cancer activity than those patients with lower levels. The
researchers concluded that the concept of anti-angiogenesis may be applicable
in the treatment of AML, particularly for those who have stopped responding
to, or who cannot tolerate standard therapies, as effective treatment
agents are limited for this group of patients and no real therapeutic
improvements have been made for 2 decades. The authors also state that
a different dosing schedule or perhaps pre-testing for VEGF may provide
improved results. Patients with refractory AML or those unsuitable for
standard therapeutic approaches may wish to speak with their physician
about the risks and benefits of participating in a clinical trial evaluating
anti-angiogenesis agents or other novel therapeutic approaches.
[Back]
Combo
Therapy Helps Leukemia Patients-(HealthDayNews-07/11/2003)
Combining the drug
Velcade (bortezomib) with experimental drugs called histone deacetylase
inhibitors may help patients with chronic myelogenous leukemia, a malignant
cancer of the bone marrow and one of the most common forms of leukemia.
A study by Virginia Commonwealth University researchers says this combination
appears to stop the growth of cancer cells by blocking key enzymes. That
action kills leukemia cells, including those that have become resistant
to other chemotherapy drugs. The findings appear in the Nov. 15 issue
of Blood.
"We found that this
combination was quite lethal to chronic myelogenous leukemia cells, which
are generally resistant to standard chemotherapy agents," the authors
write. "On its own, Velcade has not been shown to be an effective treatment
option for this form of leukemia. However, Velcade and histone deacetylase
inhibitors appear to interact synergistically to induce cell death in
chronic myelogenous leukemia, at least in the test tube, thus representing
a novel treatment approach," they add. The research is still in the early
stages, but the scientists say their initial laboratory results are encouraging.
[Back]
Formaldehyde
Linked to Leukemia, Lung Cancer-(HealthDayNews-06/11/2003)
Formaldehyde, the
pungent chemical used in everything from insect preservation to film manufacturing,
may boost rates of leukemia in exposed workers, a major federal analysis
finds. And a new study from the United Kingdom suggests such workers also
face a greater lung cancer risk from formaldehyde exposure, although they
only face a tiny risk of some rarer cancers. While the U.S. researchers
acknowledge other studies haven't been as definitive about the potential
risk, the new reports are certain to fuel the debate over the use of the
chemical in American factories. Federal regulations have limited exposure
to formaldehyde since the 1980s. However, some experts continue to call
for less research and more restrictions.
For the U.S. study,
Michael Hauptmann, a biostatistics researcher at the National Cancer Institute,
and his colleagues launched the largest-ever analysis of formaldehyde
exposure. They examined the medical records of 25,619 workers who began
working with formaldehyde before 1966 at 10 industrial plants. Researchers
followed the workers through 1994. Those exposed to high levels of formaldehyde
were up to 3.5 times more likely to develop leukemia than those at the
lowest levels. In total, 69 of the those workers died of leukemia. While
the number of deaths is small, the link between formaldehyde and leukemia
is important, Hauptmann says. "The study definitely suggests that exposure
should be kept to a minimum in the workplace and the environment," he
adds. The number of American workers exposed to formaldehyde on the job
appears to be unknown, but federal officials estimated the number at 1.5
million from 1981-1983.
Most of the workers
are exposed to formaldehyde during various types of manufacturing, including
the production of particle board, plywood, plastic and photographic film,
Hauptmann says. Scientists and pathologists also work with formaldehyde,
which acts as a preservative and gives laboratories their distinct smell.
Other uses include the manufacture of permanent press clothing, embalming
fluid and cosmetics. "It usually comes in a liquid form from which solutions
are prepared," Hauptmann says. "Then there is formaldehyde gas released
that you can inhale." His findings appear in the Nov. 5 issue of the Journal
of the National Cancer Institute.
In the other study,
which appears in the same issue, researchers in the United Kingdom examined
the medical histories of 14,014 British men who were exposed to formaldehyde
after 1937. The study had been completed in the late 1990s, but the researchers
extended it to 2000. Research in animals has suggested that formaldehyde
could contribute to two rare types of nasal cancer, but the number of
deaths from them -- three -- were actually lower than those that would
have otherwise been expected. However, the workers were up to 1.6 times
more likely to die of lung cancer. It's not clear how formaldehyde may
lead to leukemia and lung cancer. One possibility is that the chemical
launches itself into the body on tiny particles in the air and then works
itself free to create damage, Hauptman says. Epstein says both findings
are "more than enough to warrant the toughest regulatory proposals."
[Back]
Cancer
Checks for UK Hodgkin's Disease Survivors-(Reuters-10/11/2003)
Britain's Department
of Health said that 5,000 women successfully treated with chest radiation
for Hodgkin's disease in England over the past 40 years could be at increased
risk of developing breast cancer. It said cancer centers had been asked
to contact the women and offer them regular breast screening so that any
cancers they develop are detected and treated early. Professor Mike Richards,
the National Cancer Director, said the UK was believed to be the first
country to mount a national screening program following research showing
radiotherapy increases Hodgkin's disease patients' long-term risk of breast
cancer. In a statement, the department said experts estimated that women
treated in childhood had a one-in-three to one-in-seven risk of developing
breast cancer over the next 25 years. The risk was slightly lower at one-in-four
to one-in-seven for women treated in their 20s.
Hodgkin's disease
is an uncommon malignancy of the lymphatic glands. It usually affects
people in their 20s to late middle age. More than 80 percent of patients
survive at least five years. Richards stressed that radiotherapy was a
life-saving therapy and that no errors had been made in the women's treatment.
"Without radiotherapy, many of these patients would have died," he said.
"However, we now know that more of these patients are developing breast
cancer than would normally be expected. That is why we are taking action
to alert patients and to offer them screening to try and pick up any cancers
early." Nowadays, doctors often use lower doses of radiation in combination
with chemotherapy, as this is thought to provide a safer cure for many
cancers. Radiation can cause mutation of the breast cells, particularly
when given to young women. A study published in July in the Journal of
the American Medical Association showed that of 3,817 women with Hodgkin's
disease, 105 or nearly 3 percent, eventually developed breast cancer.
But women who had undergone only chemotherapy treatment with an alkylating
agent, a drug that inhibits cell division, had a 40 percent lower risk
of breast cancer. Those who received a combination of radiation and chemotherapy
still had a 1.4-fold higher risk, though the risk declined the more the
drug was used.
[Back]
Leukemia
survival shows racial divide-(ET-15/10/2003)
Even
though overall survival rates for childhood leukemia have improved dramatically
since the 1960s, children of all races are not benefiting equally, researchers
at the University of Minnesota and elsewhere have found. Black, Hispanic
and American Indian children who develop the most common form of the disease
still don't do as well as white and Asian kids, according to the study.
Researchers don't know whether the poorer outcomes for youngsters with
acute lymphoblastic leukemia are due to socioeconomic factors or differences
in the way the body responds to standard chemotherapy treatments, said
James Gurney, a research epidemiologist who is also an associate professor
of pediatrics and a member of the University of Minnesota Cancer Center.
[Back]
Siemens
to Develop New Cancer Radiation Method-(Reuters-12/10/2003)
A high-precision
radiation therapy for cancer that can be used to treat leukemia patients
and children will be developed commercially for the first time and could
reach hospitals in three years, a Siemens executive said. The technology,
for which German industrial conglomerate Siemens bought the license this
week, precisely targets tumors that were previously too dangerous to treat
with radiation, the executive of the company's medical division said.
"We're talking primarily about chondrosarcomas (tumors of cartilage cells),
brain-stem, eye and pediatric cancers, leukemia," Medical Executive Vice
President Hermann Requardt told Reuters by phone. He said an extra five
to 10 percent of cancers would be treatable with the new type of radiation.
The technique destroys
cancerous cells by shooting so-called "heavy ions" at them at extremely
high speeds. A particle accelerator fires out charged Carbon-12 nuclei
which are guided precisely to their target by magnetic fields, sparing
surrounding tissue and organs. The technology was developed by German
particle physics research institute GSI in conjunction with partners including
the German Cancer Research Center and Heidelberg University and was tested
in the German city of Darmstadt. "Since 1997, approximately 200 patients
participating in a clinical study were successfully treated with this
method," GSI and Siemens said in a joint statement. "The results exceeded
our expectations, since we were able to observe a very quick as well as
lasting tumor reaction in these patients," Juergen Debus of Heidelberg
University said in the statement.
The cost in treatment
alone of heavy-ion radiation has been estimated as being at least twice
that of conventional radiation treatment. But Requardt said that factoring
in potentially shorter treatment times and higher success rates -- saving
on prophylactic care -- the costs could be roughly comparable. "There
will be a strong desire to go for this very patient-friendly therapy,"
he said, adding that it could be carried out on an out-patient basis.
Siemens still has a few legal and regulatory steps to go through before
it will start building the machines but Requardt said he did not foresee
any difficulties. "We don't see any major hurdles," he said. "The plans
are ready and after ground-breaking we expect it will take three to four
years before we can start," he said. He added that the company already
had strong interest from investors and might finance the initiative privately
with an initial investment of up to 100 million euros ($117 million).
Requardt said it would cost around 30 million euros to build each machine,
and that the first commercially working system would probably be in Germany,
which has a mixture of public and private health care. The new technology
will complement Siemens' existing portfolio of medical products which
includes X-ray, magnetic imaging and monitoring equipment. "The technology
brings a precision of millimeters into the tumour treatment and to do
that you have to know exactly where the organs are," he said. ($1=.8522
Euro)
[Back]
Battling
Blood Cancers-(HealthDayNews-26/09/2003)
Leukemia, lymphoma
and myeloma: All three are blood cancers that can be fatal if left untreated,
and yet none can be halted with surgery. Until now, that has left chemotherapy
as the first line of defense. But new molecularly targeted drugs are being
hailed as precise and powerful weapons against cancers that are notoriously
hard to treat. "Unlike solid tumors, where surgery can be used to remove
the tumor at an early stage and the patient might not be treated with
anything else, we can't do that in blood cancers," explains Alan Kinniburgh,
vice president of research at the Leukemia & Lymphoma Society. "This was
the first place chemotherapy was brought to bear and was successful. We're
now at a point from where in 1960 about 4 percent survived longer than
five years and now 85 percent do," Kinniburgh says. To push beyond that
85 percent mark, researchers are pouring their energy into the development
of these molecularly targeted drugs, which attack diseased cells directly
and produce fewer side effects in the process.To
heighten awareness of these developments, the Leukemia & Lymphoma Society
has also declared September as Leukemia, Lymphoma and Myeloma Awareness
Month.
More than 100,000
Americans will be diagnosed with one of these three blood cancers in 2003.
That's not counting hundreds of thousands more who are living with one
of the diseases. Lymphoma is the most common type of blood cancer, representing
57 percent of all cases. Leukemia makes up 30 percent of all cancers diagnosed
in children under the age of 15. Leukemia refers to cancer of the bone
marrow and blood cells. The two major categories are myelogenous and lymphocytic.
Each of these can be further subdivided into acute (with a rapid onset)
and chronic (which comes on more slowly). Lymphomas are cancers that arise
when lymphocytes -- a type of white blood cell -- become malignant. The
two main types of lymphoma are Hodgkin's and non-Hodgkin's. Myeloma affects
the plasma cells, or white blood cells found primarily in the bone marrow,
and it interferes with the body's immune system.
No one is sure what
causes these cancers, although they are thought to arise when a single
cell with a genetic flaw starts replicating uncontrollably. While chemotherapy
and other conventional treatments are still being used, the breakthroughs
are happening with molecularly targeted drugs. "We've really spent a lot
of time in the last couple of decades finding altered genes in cancer
and now we're actually starting to develop molecular-targeted therapy
to go after these altered genes," says Dr. Donald Small, an associate
professor of oncology, pediatrics and cellular and molecular medicine
at the Johns Hopkins University School of Medicine.
Specifically, scientists
are looking at a class of frequently mutated genes called tyrosine kinases,
which seem to be involved in many of the blood cancers, Small says. Chronic
myeloid leukemia, or CML, for instance, involves a genetic flaw in one
of these genes that produces an abnormal protein. This triggers a signal
that pushes cells to start reproducing. A new drug, Gleevec, goes inside
the abnormal protein and commands it to stop sending the signal. Because
the drug is so finely targeted, it has few side effects. Gleevec now appears
to be emerging as the drug of choice for CML, Small says.
Similarly promising
research is taking place with acute myelogenous leukemia, or AML, a disease
whose cure rate hovers at 20 percent to 30 percent. "It requires such
intensive chemo that a lot of people consider patients over 60 or 65 can't
be treated aggressively enough to have any chance," Small says. "We really
need new types of therapies and it may well be that, when chemo is combined
with some of the targeted therapies, we could see a big impact." Small
and other researchers around the country are currently conducting trials
with new molecularly targeted drugs that inhibit another tyrosine kinase
gene, this one called FLT-3. "There are patients who are having responses,"
Small reports. In the case of AML, however, more than one drug will probably
be needed to affect the multiple genes that are at fault. "In chronic
phase CML, it's probably a single gene, so it's a lot easier to target;
you're basically hitting the whole disease," Small says. "In AML, there
are probably three or four or more altered genes."
There are other categories
of therapy as well. Chemotherapy and radiation have both been around for
half a century but can entail significant side effects. "They kill growing
cells and they kill the fastest first and that's fine, but it's kind of
a blunt instrument when it's used," Kinniburgh says. A newer approach
is called immunotherapy, also targeted but not usually considered molecularly
targeted. This involves developing antibodies that attack part of the
cell surface, causing the cell to die. These are also called monoclonal
antibodies. And vaccines could help the patient's own immune system fight
off blood cancer. No vaccines are yet approved, though some are in advanced
clinical trials. Many patients also need bone marrow transplants, which
seek to replace a person's depleted healthy blood-forming cells with another
person's. "It's kind of a hybrid system of using someone else's immune
system to reconstitute your own immune system after very vigorous chemo
and/or radiation," Kinniburgh explains. "You just have to watch out for
those cells attacking the body because there are differences. It kills
patients every day."
Finally, there have
been some recent reports that postmenopausal women who take aspirin regularly
may have a lower incidence of acute leukemias. Mostly, though, the world
is moving in the direction of highly targeted treatments. "Over time it
will be more and more designer-type therapy," Small says. "Eventually,
it may turn out that a patient comes in with a certain type of tumor.
We take cells, see what genes are altered and pull compound A for this
mutation and compound C for that one. It will be very, very specific and
very much designer-type therapy."
[Back]
Study:
Mono Boosts Risk for Hodgkin's-(Associated Press-02/10/2003)
Young adults who
get mononucleosis, the "kissing disease," have more than double the risk
of developing a rare type of cancer, a Danish study found. Doctors have
long suspected a link between mononucleosis and Hodgkin's disease, a highly
treatable cancer of the lymph system. But the role played by the common
virus that causes mono was uncertain. The virus, Epstein-Barr, is found
in about one-third of Hodgkin's tumors. In a study of over 63,000 young
adults suspected of having mono, the researchers found that those who
got mono had a higher-than-average chance of getting Hodgkin's, and the
risk lasted for two decades. There was no increased risk for those who
did not have mono. "I think it removes the last shade of doubt that the
virus actually has something to do with causing Hodgkin's disease," said
Dr. Richard Ambinder of Johns Hopkins School of Medicine, who was not
involved in the research. "The flip side to that is that everyone's got
the virus, so it can't possibly be the whole story."
The Danish researchers
stressed that Hodgkin's disease, also known as Hodgkin's lymphoma, is
uncommon. About one in 1,000 of young adults with mono will get the cancer,
they said. "Only in rare circumstances will this lead to the development
of Hodgkin's lymphoma. So there's no reason for any panic," said Dr. Mads
Melbye, one of the researchers at Statens Serum Institut, the Danish equivalent
of the U.S. Centers for Disease Control and Prevention. The study is reported
in New England Journal of Medicine. Hodgkin's accounts for less than 1
percent of cancer in the United States, and is most common in those ages
15 to 34 and those over 55. According to the American Cancer Society,
about 7,600 new cases will be diagnosed this year.Dr.
Len Lichtenfeld, deputy chief medical officer for the American Cancer
Society, said parents and patients should not be overly concerned about
the study's findings. "This doesn't change our practice or our patterns.
It enhances our knowledge," Lichtenfeld said. Ambinder said the research
raises the possibility of preventing Hodgkin's in those who have had mono
or diagnosing it earlier. "There's fertile ground for more research,"
he said.
Most everyone is
infected at some point with the Epstein-Barr virus, which is spread through
saliva, and the virus remains dormant for life. In children, there are
usually few or no symptoms from the infection. But when exposure first
occurs in adolescence or later, it can cause mono. Symptoms include fever,
sore throat, swollen glands and fatigue. The research included 38,555
Danish and Swedish patients diagnosed with mono and 24,614 Danish patients
who were tested for mono but did not have it. Cancer registries were checked
to determine how many later developed Hodgkin's disease, which typically
occurred four years after mono. Sixteen of 29 Hodgkin's tumors tested
from the mono group contained the virus. The findings suggest that there
are other causes for Hodgkin's besides the Epstein-Barr virus, Melbye
said. "It's a cause, not THE cause," he said. Melbye said the study's
results should apply to the United States, which has rather similar rates
of mono and Hodgkin's.
[Back]
Childhood
Cancer Takes Toll on Survivors-(HealthDayNews-23/09/2003)
Survivors of childhood
cancer are much more likely than their healthy siblings to suffer from
a variety of health problems when they reach adulthood. The increased
risk was particularly pronounced among women, those with lower educational
levels, and those with low household incomes. These results, from an unprecedented
study of almost 10,000 cancer survivors, appears in the Sept. 24 issue
of the Journal of the American Medical Association. Because survival rates
for childhood cancers are now upwards of 78 percent, the number of people
who have lived five or more years beyond their initial diagnosis is growing.
For the first time, scientists and the world can see the long-term consequences,
which can include second cancers, heart disease, infertility, obesity
and psychological distress.
The authors of this
study compared the health status of 9,535 adult participants of the Childhood
Cancer Survivor Study with 2,916 of their siblings. All of the cancer
survivors had survived at least five years after their diagnoses. Six
areas of health were assessed: general health, mental health, functional
status, activity limitations, cancer-related pain and cancer-related anxiety
or fears. The first four areas were assessed in the sibling control group.
Participants were asked to give their own perceptions of their health
status, something that distinguishes this study from many others. According
to this self-reported data, cancer survivors were 2.5 times more likely
to report adverse general health, 80 percent more likely to report mental
health problems, 2.7 times more likely to report limitations in activity,
and 5.2 times more likely to report functional impairment, compared with
their siblings. Compared to male survivors, females were 40 percent more
likely to report at least one adverse health effect, 20 percent more likely
to have general health problems, 40 percent more likely to have functional
impairment, 70 percent more likely to suffer activity limitations, and
60 percent more likely to suffer from anxiety. Survivors with a lower
educational level were 2.6 times more likely to have general health problems,
while those with an annual income of less than $20,000 were 1.8 times
more likely to report such problems. Almost half (44 percent) of the survivors
reported adverse effects in at least one of the six areas. On the other
hand, only 10.9 percent perceived they had impaired health.
"The vast majority
perceived their health as very good, which is testimony to how resilient
they are after this experience," says study author Dr. Melissa Hudson,
director of the After Completion of Therapy Clinic at St. Jude Children's
Research Hospital. "[Having cancer] affects them emotionally, psychologically
and physically, and the vast majority are able to move beyond that cancer
experience and adapt to whatever chronic illnesses or disabilities they
have." But the U.S. health-care system is not set up to handle the long-term
health problems that do arise. "There's really not a very good system
in this country for providing long-term care," says Dr. Cindy L. Schwartz,
author of an accompanying editorial and an associate professor of oncology
and pediatrics at the Johns Hopkins Kimmel Cancer Center in Baltimore.
Kids with cancer
become adult survivors who are no longer allowed by health insurers to
visit their treating institution. Many adults move to other geographical
locations. At the same time, Schwartz adds, the disease and treatments
tend to be unique and most primary-care providers do not have the knowledge
or experience to deal with them. In some cases, the idea of long-term
survivors is relatively new, so experts aren't even sure what to expect.
"It's an ongoing, moving target," Schwartz says. "The problem with late
effects is that many are things that don't show up for 10 or 15 years
. . . It would be nice to be able to prepare [survivors] as to what they
might expect." As it stands, however, good mechanisms for such follow-up
do not exist. "We're trying to make the medical community aware of this,"
Hudson says. "This is such a small percentage of each individual primary-care
provider's practice. We want to make this as easy as possible for primary-care
providers. We want them to know where resources are without becoming an
expert."
[Back]
Children
with Acute Lymphoblastic Leukemia Treated with Radiation to the Brain
Suffer Long-Term Side Effects-(ET-17/09/2003)
According to recent
results published in The New England Journal of Medicine, children diagnosed
with acute lymphoblastic leukemia (ALL) who receive treatment including
radiation therapy to the brain are at an increased risk of suffering long-term
side effects. Acute lymphoblastic leukemia (ALL) is a cancer of the bone
marrow and lymph system. The bone marrow produces early blood-forming
cells, called stem cells, which grow and mature into the three blood cell
types: white blood cells, which fight infection; red blood cells, which
carry oxygen to tissue; and platelets, which help blood to clot. ALL is
characterized by uncontrolled production of immature lymphocytes (white
blood cells), of which there are two types: B and T cells. These immature
lymphocytes never mature enough to perform their specific function of
fighting infection. In addition, these rapidly dividing cells crowd out
and suppress the formation of other important blood cells, such as red
blood cells, platelets and other white blood cells. ALL is an aggressive
cancer that must be treated aggressively for optimal chances of a cure.
The central nervous
system (CNS), including the brain and spinal column, is a common site
for cancer to recur in patients with ALL. Historically, patients were
treated with radiation to the brain alone or brain and spinal column to
reduce the risk of a recurrence in the CNS. Due to known long-term side
effects that can be caused by irradiation to the CNS, present treatment
for the prevention of a recurrence in the CNS is chemotherapy delivered
systemically (full-body) or intrathecally (spinal column). Researchers
from St. Jude Children's Research Hospital have recently compared long-term
side effects of patients who had received or not received radiation to
the brain for treatment of childhood ALL.
This study involved
856 patients who had survived at least 10 years following treatment for
ALL; 597 of whom received radiation therapy and 259 who had not. The risk
of developing a second cancer was 21% in patients who received radiation
therapy, compared with less than 1% in patients who did not receive radiation.
Survival at approximately 30 years following treatment was 95.3% in the
group of patients treated with radiation therapy, compared with 98.3%
in patients not treated with radiation, which is the approximate survival
rate of the general population. Furthermore, patients treated with radiation
therapy had significantly higher than average rates of unemployment and
women in this group were less likely to be married. The researchers concluded
that brain and spinal radiation therapy in childhood patients diagnosed
with ALL can lead to long-term consequences, including an increased risk
of developing a second cancer. Since the vast majority of pediatric patients
treated for ALL achieve long-term survival, it is important for both patients
and physicians to be aware of long-term sequelae of CNS radiation. Patients
who are survivors of childhood ALL and received CNS radiation should discuss
risks associated with this therapeutic regimen with their physician.
[Back]
Child
Cancer Survivors See Side Effects-(AP-26/08/2003)
Children's chances
of beating cancer have gotten better but as many as two-thirds of survivors
are likely to experience a delayed side effect from the disease or the
treatment, said a report. About a quarter of survivors may experience
severe or life-threatening side effects that do not show up immediately
but could affect things like growth, fertility, heart function, muscle
movement or cognitive activity, said the study by the Institute of Medicine,
an arm of the National Academy of Sciences. Susceptibility to these late
side effects depends on the child's age at the time of diagnosis, how
much chemotherapy and radiation were used as well as the severity and
location of the cancer. The late side effects can occur in follow-up treatment
or they may develop in adulthood, complicating their identification and
treatment, the report said.
Also, because treatments
for cancer have evolved in recent years, the delayed side effects are
also changing. In 1997, 270,000 Americans of all ages had survived childhood
cancer - including about 1 in 640 adults aged 20 to 39. That was up from
1970, when children diagnosed with cancer had little chance of being cured.
The rising number of survivors has made the long-term care issues more
apparent. "We're learning more as the first generation of childhood cancer
survivors get older," said Stuart Kaplan, a staff physician in a follow-up
cancer care clinic at St. Jude Children's Research Hospital in Memphis,
Tenn. Looking for known threats and treating side effects early can help
to minimize the damage these side effects can cause, he said. "Directed
screening is very important, and it's really the job of the primary care
providers," he said, adding that educating patients is also important
"because the onus is often on them."
The report recommends:
-Developing guidelines
for the follow-up care of childhood cancer survivors. -Creating links
between primary physicians and specialists.
-Raising awareness
of the late side effects that threaten cancer survivors. -Stepping up
research to prevent late side effects.
[Back]
Radiation
Not Needed for Childhood Cancers-(HealthDay News-13/08/2003)
Two new studies show
radiation can affect how long and how well children survive cancer. The
first study found children with acute lymphoblastic leukemia who received
chemotherapy but not radiation to the brain area tended to live longer
and with a better quality of life than those who got both treatments.
But the long-term outcomes for both groups were quite high.
The second study
found the risk of hospitalization for psychiatric disorders is no higher
among survivors of cancer in childhood or adolescence. The one striking
exception was among those who had had brain tumors, for which radiation
is the standard treatment. Both reports appear in the New England Journal
of Medicine. "Neither [study] has anything smashingly new to say, but
they are good studies because they involve a relatively large number of
patients that confirm some things that we already knew to some extent,"
says Dr. Joseph V. Simone, author of an accompanying editorial.
Referring to the
first study on children with acute lymphoblastic leukemia, Dr. William
Carroll, division chief of pediatric oncology at New York University Medical
Center, says, "Cure rates for childhood leukemia are one of the success
stories." "The question has been now that we're curing all these patients,
what problems are going to surface 20, 30 years later," he adds. "This
study shows quite strikingly that the survival of these patients is no
different from the general population so once you've gone that long you
should be considered normal. And that has profound implications for everything
from getting insurance to how you're viewed in society. When we say cure,
we mean cure."
According to the
National Cancer Institute, acute lymphoblastic leukemia, or ALL, is the
most common form of leukemia in children and the most common type of childhood
cancer. Patients suffering from this disease have too many underdeveloped
white blood cells. The research team looked at 856 patients who had been
treated in clinical trials at St. Jude Children's Research Hospital in
Memphis between 1962 and 1992. The patients, all of whom had survived
at least 10 years, were divided into two groups: Those who had received
radiation and those who had not. Participants who did not receive radiation
therapy and who had survived to the 10-year mark without any new or recurring
illness can expect to live a normal life, the authors conclude. "Normal"
refers both to length and quality of life. "Patients who never received
radiation to the brain had normal survival compared to the general population,"
says study author Dr. Ching-Hon Piu, director of the Leukemia Lymphoma
Division at St. Jude. "Employment and marriage rates were the same as
the general population, as well as insurance rates."
The mortality rate
for the group that received radiation was slightly higher than the general
U.S. population. While men and women in the radiation group had health
insurance rates similar to the general population, they had higher unemployment
rates. In the radiation group, 15.1 percent of men were unemployed, compared
to 5.4 percent of the general population. And 35.4 percent of women were
unemployed, versus 5.2 percent of the general population. Women who had
received radiation were also less likely to be married (only 35.2 percent
were married, versus 48.8 percent of the general population). Piu attributes
these differences to brain damage resulting from the radiation treatments.
For the second study
on hospitalization for psychiatric disorders, the study authors, based
in Denmark, looked at 3,710 people who had survived at least three years
after being diagnosed with cancer in childhood or adolescence. Although
more people in this group were hospitalized for a psychiatric condition
than would be expected in the general population, that higher number was
entirely due to brain tumor survivors. These individuals were 80 percent
more likely to be hospitalized. "We've known for 15 or 20 years that a
child, depending on the [type of cancer] and the age of the child, runs
a risk of neuropsychosocial effects," Simone says. "We've spent a long
time figuring out what it is about the radiation to try to refine treatment."
Largely as a result of this long-running research, radiation is no longer
used as a primary treatment for most childhood cancers (the notable exception
being brain cancer). "We know now that with chemotherapy these kids do
fairly well so there's really no need to irradiate them unless they have
overt central nervous system disease," says Dr. Shipra Kaicker, a pediatric
hematologist/oncologist at Maimonides Medical Center in New York City.
The point, Simone
says, is that follow-up is necessary to assess and improve upon treatment
for childhood cancer. The psychiatric study was possible because of the
exceptionally thorough health-care records kept in Denmark, which has
universal health care. In the United States, many patients are lost to
follow-up, suggesting the need for more systematic methods for following
childhood cancer patients. Simone cites a report due out in October from
the U.S. Institute of Medicine that will try to provide a road map for
studying these individuals.
[Back]
Common
Childhood Cancer Can Be Cured-(Reuters Health-14/08/2003)
Acute lymphoblastic
leukemia (ALL), the most common type of childhood cancer, can be cured
and kids who survive it can have a normal lifespan, new research suggests.
ALL involves the uncontrolled growth of blood cells called lymphocytes.
About 3000 children are diagnosed with ALL each year in the US. ALL is
slightly more common in boys than girls and it is usually diagnosed between
three and five years of age. "We were interested in determining whether
patients with ALL could be cured," lead author Dr. Ching-Hon Pui, from
St. Jude Children's Research Hospital in Memphis, Tennessee, told Reuters
Health. "The disease is associated with late relapses, but now with 30
years of follow-up, I think we can confidently say that indeed ALL can
be cured."
In the past, children
who were treated and went five years with no return of their disease were
classified as cured, Pui noted. The new findings, however, indicate that
10 years without disease is needed before a patient can be considered
cured, he added. The current results are based on a study of 856 ALL patients
who were treated between 1962 and 1992. All of the patients had survived
at least 10 years with no return of their cancer. The findings are reported
in The New England Journal of Medicine.
ALL patients treated
with chemotherapy lived just as long as healthy individuals. The patients
who also received radiation--a treatment often given to high-risk patients--had
slightly lower survival. Treatment with radiation was also tied to other
problems, the investigators point out. For example, such therapy seemed
to raise a patient's chances of developing other cancers. "This is the
first study to show that the adverse effects of radiation can occur 20
to 30 years after treatment," Pui said. "We really didn't appreciate that
patients could develop (other cancers) beyond 20 years." Still, in general,
the cancers that arose were not that serious and were easily treated,
he added. "A study is currently underway at St. Jude to see if we can
avoid (using radiation) in high-risk ALL patients," Pui noted. So far
the results look encouraging, he added.
[Back]
Hodgkin's
Disease Therapy Doesn't Have to Trigger Breast Cancer-(HealthDayNews-02/07/2003)
Doctors have long
known that radiation therapy increases the risk that people with Hodgkin's
disease might develop other forms of cancer, including blood malignancies
and solid tumors. In young women with Hodgkin's disease, the threat of
breast cancer is a particular concern following radiation. But new research
suggests this hazard can largely be avoided with careful attention to
the hormones of women undergoing treatment for Hodgkin's disease. In particular,
drugs that interfere with the sex hormone estrogen -- such as the cancer
drug tamoxifen -- may help. "Tamoxifen has not been used in this population,
but it might be something that we should consider," says research leader
Flora van Leeuwen, an epidemiologist at the Netherlands Cancer Institute
in Amsterdam. A report on the findings appears in the Journal of the National
Cancer Institute.
Hodgkin's disease,
also known as Hodgkin's lymphoma, is a blood-related cancer that affects
some 7,000 people a year in the United States, according to the Leukemia
and Lymphoma Society. Treatment advances since World War II, including
radiation and a variety of drug combinations, have greatly improved the
odds for patients with the disease, and five-year survival rates hover
around 90 percent. Still, the threat of "secondary" cancers brought on
by treatment clouds the successes of Hodgkin's therapy. Although many
of these secondary malignancies aren't especially serious, some can be
life-threatening.
The new study made
two important findings, says van Leeuwen. First, it showed that a woman's
risk of breast cancer after radiation treatments for Hodgkin's disease
climbed based on the dose she received. Women who got the most radiation
-- at least 38.5 grays to their breast -- had 4.5 times the risk of developing
breast cancer as those who got less than 4 grays. "In Hodgkin's disease
treatment, the mediastinal lymph nodes are irradiated and various portions
of the breast receive different doses" in the process, van Leeuwen says.
"Calculating this dose was a labor-intensive part of the study, but crucial."
The chances that
radiation for Hodgkin's disease would promote breast cancer dropped sharply,
though not back to normal, in women whose treatment also called for chemotherapy,
van Leeuwen says. Compared with women who received radiation alone, those
who also underwent chemotherapy had about a 60 percent smaller risk of
breast cancer, the study found. The likely reason: Chemotherapy can hasten
the onset of menopause, van Leeuwen says. Since menopause is a hormone-suppressed
state, and many cases of breast cancer are sparked by the female sex hormone
estrogen. Inducing menopause may blunt the ability of radiation to trigger
breast tumors, she says. "We already knew that radiation produces breast
cancer," van Leeuwen says. "We now know with this study that with higher
[doses], the risk is higher, but we now see that there is a way to substantially
reduce the risk of these cancers."
[Back]
New
Cancer Drug May Find Wider Use-(HealthDayNews-25/06/2003)
A drug with an improbable
molecular target has been so effective against a particularly recalcitrant
form of bone marrow cancer that researchers plan to sic it on other cancers.
The drug is bortezomib, which is being marketed as Velcade by Millennium
Pharmaceuticals. It inhibits the activity of proteasome, a molecule essential
to the activity of all cells -- so essential that many thought it would
cause unacceptable damage to healthy cells as a cancer treatment. But
laboratory studies, by Dr. Kenneth D. Anderson of the Dana-Farber Cancer
Institute in Boston and Dr. Richard J. Ford of the M.D. Anderson Cancer
Center at the University of Texas in Houston among others, showed that
it could act against cells of multiple myeloma and other blood cancers
without disabling side effects. A study appearing in the New England Journal
of Medicine found that Velcade slowed the progress of multiple myeloma
in 67 of 193 patients in whom other drugs were ineffective, with the responses
lasting an average of 12 months. The response was complete or near-complete
in 19 of those patients, and the average survival time was 16 months,
much longer than usually seen in such cases.
"It is being tested
in other cancers now," says Dr. Robert Z. Orlowski, an assistant professor
of medicine and hematology/oncology at the University of North Carolina
and a member of the research group. "The results are a little early, but
there are encouraging results against some blood cancers, such as non-Hodgkins
lymphoma, and it is being used in combination with other drugs in solid
tumors."
Promising results
against another hard-to-treat blood cells cancer, mantle cell lymphoma,
were reported earlier this month at the American Society of Clinical Oncology's
annual meeting by M.D. Anderson researchers. Of 11 patients treated with
Velcade, three had complete responses, meaning that no trace of the disease
could be found; four had partial responses, with the disease stabilized
in the remainder. "Mantle cell lymphoma is currently nearly intractable,
with a long-term survival rate of about 10 percent," says Alan Kinniburgh,
vice president of research administration at the Leukemia and Lymphoma
Society.
Proteasome has long
been known to act as a kind of garbage disposal system of the cell, destroying
damaged proteins, Kinniburgh says. Millennium Pharmaceuticals developed
the drug as a treatment for muscle wasting conditions, to prevent the
destruction of proteins needed for cell growth. Research showing that
it could selectively stop the growth of cancer cells have led to its widening
use. "Velcade works on the fundamental regulators of cell growth, which
means that in addition to blood cancers, the drug has potential to treat
cancers of the breast, colon and prostate," Kinniburgh says. One welcome
development was last month's rapid approval of Velcade by the Food and
Drug Administration, Orlowski says. The quick action is "exactly how modern
medical and laboratory work should be treated," he says.
[Back]
Aspirin
May Cut Risk of Adult Leukemia-(HealthDayNews-16/06/2003)
Postmenopausal women
who take aspirin two or more times each week may lower their risk of developing
leukemia by more than 50 percent compared with women who do not take the
drug. Although these results are preliminary, this could signal yet another
usage for the miracle drug that was invented more than a century ago and
already has been shown to have a beneficial effect on colon cancer and
heart disease. "I was very excited about the findings because leukemia
is one of those cancers that has a high fatality rate," says Julie Ross,
senior author of a paper appearing in the June 13 edition of Cancer Epidemiology,
Biomarkers and Prevention. "If this were to hold up in other studies,
we're seeing a real reduction in risk." "It
certainly is a teaser in the sense that there seems to be a 50 percent
reduction in the incidence of leukemia," says Alan Kinniburgh, vice president
of research at the Leukemia and Lymphoma Society. He nevertheless adds
that "more studies are needed to see if this holds true."
Little is known about
the causes of adult leukemia, which accounts for about 5 percent of all
newly diagnosed malignancies in the United States. Without information
on causes, little can be done in the way of prevention. "With blood cancers,
we don't really have programs to give to patients to try to avoid these
diseases," Kinniburgh says. "The origin of most leukemias is unknown."
The authors analyzed information on 28,244 women who participated in the
Iowa Women's Health Study, which looked at overall health, lifestyle,
behaviors and incidence of cancer. The women were sent a mail survey in
1992 asking them, among other things, how often they took aspirin, other
NSAIDs (nonsteroidal anti-inflammatory drugs) or arthritis medicine. All
of the women were cancer-free (except possibly for skin cancer) at the
beginning of the study. The study authors then cross-referenced these
same women with the National Cancer Institute's Surveillance, Epidemiology
and End Results (SEER) Program, which tracks cancer diagnoses in certain
areas, including Iowa.
Between 1993 and
2000, 81 women in the group had developed leukemia. Women who reported
using aspirin at least two times a week had a more than 50 percent lower
risk of developing leukemia compared to women who reported no aspirin
use. There were other small effects depending on what drugs the respondents
used, but they were not statistically significant and "the protective
effect appears to be with aspirin," says Ross, an associate professor
of pediatrics and a member of the University of Minnesota Cancer Center
in Minneapolis. The study has several advantages. It is the first prospective
study to look at aspirin use in relation to adult leukemia, meaning it
looked forward rather than backward. It also compared use of aspirin to
other NSAIDs.
Nevertheless, there
are some limitations. For one thing, the researchers didn't know exactly
how much aspirin the women were taking, or for how long. No one knows
why aspirin might have a protective effect against this or any other type
of cancer. "I have no idea what the mechanism might be," Ross says. "It
might come down to something such as platelet aggregation. When platelets
clot, growth factors are released locally. Just by reducing that activity,
are you reducing overall risk?" Kinniburgh adds aspirin may have an effect
on certain inflammatory processes taking place in leukemia. Ross has just
submitted a grant proposal to the National Institutes of Health to conduct
a large case-control study of adult leukemia and aspirin regimens.
[Back]
Gene
Therapy Technique May Pose Harm: Study-(Reuters Health-12/06/2003)
Scientists announced
that their research into the a particular type of gene therapy raises
important questions about the safety of using retroviruses to carry genes
into people. In gene therapy, a vector -- usually but not always a virus
-- is used to carry a healthy gene into the cells of patients. If it works
correctly, the virus inserts its DNA and the new gene into cells and corrects
the genetic defect. Earlier this year the Food and Drug Administration
halted certain gene therapy trials after two boys in France developed
leukemia while they were taking part in a gene therapy trial that aimed
to bolster bone marrow with genetically engineered immune cells. The treatment
appeared to be working remarkably well in 10 of the group of 11 boys who
had a hereditary disease that left them without an immune system.
The leukemia cases
prompted researchers to speculate that the retroviral vector used in the
trial may have been integrated near a known cancer-promoting gene. In
the current study, lead investigator Dr. Shawn M. Burgess and colleagues
analyzed where in the human genome two types of retroviruses are likely
to permanently integrate. The researchers looked at one of the most commonly
used retroviruses in gene therapy -- murine leukemia virus (MLV), a mouse
virus that can infect human cells. And they also looked at another retrovirus
-- HIV-1. "MLV was used in the French study where two children, of 11,
developed leukemia," said Burgess. Burgess's team looked at 903 MLV and
379 HIV-1 integrations and found two different results for the two viruses.
"This was unexpected," he said. "HIV-1 likes to integrate anywhere in
genes, and MLV likes to integrate around the beginning of genes where
the important regulatory sequences are," he explained. The main finding,
according to Burgess, is that viruses integrate into sequences non-randomly
and it appears that every virus will do this differently. "Thus, nothing
about the safety of a particular retroviral treatment can be assumed,"
he said.
In the past the assumption
was that the integrations were random and that the risk was low that the
virus would integrate somewhere risky in the DNA code, noted Burgess,
who is with the National Human Genome Research Institute in Bethesda,
Maryland. "This is apparently not true," he said. What's more, the findings
seem to jibe with what happened in the two children who developed leukemia.
"The integrations that are believed to cause the problems both fit the
favorite-site profile we determined for MLV," Burgess said. "Thus, the
risks must be higher than we originally thought," he added. Burgess noted
that the findings, which are published in the journal Science, are the
first-ever documentation of a large number of integration sites for two
viruses showing they behave very differently and there are inherent risks
in using them for gene therapy. As such, he recommends that "any new vector
should be profiled to determine the integration biases of the vector to
be used to help evaluate relative risk." The new discovery may very well
be a set-back for gene therapy, as there are few alternatives to using
retroviruses as vectors, according to Burgess. "None of (the other types)
are as far along as the retroviral vectors," he said. "They all have their
own problems that are even larger than the viruses." "At the moment, (retroviral
vectors) still seem the most promising, even with the associated risk,"
he added.
[Back]
New
Drug Regimen Helps Hodgkin's Disease-(HealthDayNews-11/06/2003)
Various alphabet
soups of cancer drugs are used to treat advanced Hodgkin's disease, a
form of blood-related cancer that strikes the lymph system. But which
combination of medicines works best hasn't been clear. A new German study
helps answer the question. It found better survival rates and more remissions
on a new drug regimen than on an older therapy or on a less-potent version
of the new treatment. The new regimen, high doses of seven drugs known
by the initials BEACOPP, had a five-year survival rate of 91 percent,
several points better than the next most effective alternative. The drugs
attack Hodgkin's disease in a variety of ways, from damaging DNA in cancerous
cells to suppressing the formation of those cells in the first place.
The regimen does have a few drawbacks: It's hard to tolerate and administer;
it's costly; and, more significantly, it has a propensity to cause other
blood cancers.Still,
the researchers say those cancers are usually manageable and the treatment's
overall effectiveness outweighs its downside.
Dr. James Armitage,
a lymphoma expert and dean of the University of Nebraska's College of
Medicine, calls the study "provocative." Although the researchers compared
BEACOPP to a treatment, called COPP-ABVD, that's outmoded by U.S. standards,
"it's higher doses of more drugs quicker and that might give an advantage."
Hodgkin's disease patients in the United States typically receive the
regimen ABVD-COPP. ABVD has fallen from favor after U.S. studies didn't
support its use, Armitage says. So before BEACOPP becomes the standard
of care here, it will have to be pitted against ABVD. "If it is better
than ABVD, then I have no doubt that it will get adopted," he says. A
report on the findings appears in the June 12 edition of The New England
Journal of Medicine.
Hodgkin's disease,
also known as Hodgkin lymphoma, is a blood-related cancer that affects
some 7,000 people a year in the United States, according to the Leukemia
& Lymphoma Society. Treatment advances since the 1960s have greatly improved
the odds for patients with the disease, and five-year survival rates hover
around 90 percent. Many patients can realistically hope to be cured of
the disease.
In the latest study,
Dr. Volker Diehl, of the University of Cologne, led a research team that
followed 1,201 men, women and teenagers with advanced Hodgkin's disease.
At the start of the study in 1993, patients were randomly given COPP-ABVD,
BEACOPP or high-dose BEACOPP. By 1996, it was clear that COPP-ABVD was
inferior to either of the other two treatments, so no additional patients
were assigned to that group. Alan Kinniburgh, vice president for research
at the Leukemia & Lymphoma Society, in White Plains, N.Y., says the study
results build a strong case for using BEACOPP in patients with advanced
Hodgkin's disease. But while the study is good news for most people with
the cancer, some forms of the disease are more lethal than others. And
in these patients, the survival rates can be quite low.
"There are some aggressive
forms, and we need to find new therapies," he says. Kinniburgh's foundation
is pushing for scientists to develop vaccine-based approaches to the disease.
In about 30 percent of people with Hodgkin's disease, the cancerous cells
are infected with Epstein-Barr virus, the microbe that causes mononucleosis.
"It probably drives the growth of those malignant cells," Kinniburgh says.
Other viruses may influence the course of the cancer, too, he says, so
bolstering the body's defenses against these pathogens may help fight
Hodgkin's disease. In an unrelated study also appearing in the same journal,
European researchers say radiation after chemotherapy doesn't help Hodgkin's
patients live longer or reduce their odds of the disease's return. Radiation
of areas affected by cancer -- so-called "involved fields" -- does appear
to improve results in patients in partial remission. Yet it does so with
the price of an increased risk of other cancers, the study says. "Particularly
in young patients, radiation would be something to be avoided, especially
if the involved field is a lung or other major organ," Kinniburgh says.
[Back]
Heart
Concerns Linger for Childhood Cancer Survivors-(ET-05/06/03)
Survivors of childhood
cancer need to keep a closer watch on their hearts than previously believed,
according to new research. Doctors say the harmful cardiac effects of
cancer treatments may be more extensive than they realized. "It's very
important for the general medical community to be aware that this population
is at greater risk (for heart problems)," said study co-author Steven
Lipshultz, MD, an oncologist and pediatric cardiologist at the University
of Rochester Medical Center. Likewise, survivors need to be sure their
doctors know their cancer treatment history so they can monitor them for
heart troubles they might not otherwise look for. Lipshultz and colleagues
presented the findings from two studies at last weekend's annual meeting
of the American Society of Clinical Oncology.
Doctors have long
known that certain types of cancer therapy - particularly treatment with
drugs known as anthracyclines - can cause cardiomyopathy, a weakening
of the heart muscle that can lead to congestive heart failure. But these
medications are critical to treat certain cancers, so doctors generally
recommend that survivors of childhood cancer who received this therapy
be monitored over the long term for this particular problem. What Lipshultz
and his colleagues discovered is that many survivors also show other signs
of heart disease like atherosclerosis (fatty deposits in the arteries),
high cholesterol, and high blood pressure. Doctors typically don't look
for these conditions in this group of patients, Lipshultz said.
In one of their studies,
the researchers compared three groups of people: 132 childhood cancer
survivors who had received potentially heart-damaging anthracycline chemotherapy
or radiation to the heart, 41 survivors who had been treated with other
cancer therapies, and 59 siblings of the survivors from both groups who
had never had cancer. The survivors had all received their last treatments
five or more years before the study. Lipshultz said the researchers put
the study groups through "every test you could think of" for heart conditions;
they measured body composition, looked at hormone levels, endocrine levels,
heart muscle strength, other muscular function, and more. They found that
patients who had received anthracycline therapy showed an enhanced risk
for accelerated atherosclerosis - something that puts them at risk of
a heart attack. Even the survivors who did not have heart-damaging therapy
showed signs of premature heart disease, Lipshultz said. They had a higher
risk than their cancer-free siblings, though not as high as the other
group of survivors. "Basically all survivors of childhood cancer should
be screened at some regular set of intervals for risk of atherosclerosis,"
Lipshultz said. "If you find it, you can potentially intervene with preventive
strategies" like diet and exercise changes, or even medication, he said.
In the second study,
Lipshultz and his collaborators examined 48 people who had been successfully
treated for Hodgkin disease about 15 years earlier, most when they were
teenagers. Almost all of them had been treated with radiation to the chest,
including the heart. None of the patients had any known heart problems,
and in health and quality of life questionnaires, all said their overall
health was good or better. But the researchers found that their hearts
were not normal. About 60% of the patients had some type of heart valve
problems - their valves were "sticky" or leaky. And more than half showed
signs that the electrical impulses that control the heart's beating were
slowing down. Lipshultz said some of the survivors also showed evidence
of scar tissue in the main pumping chamber of the heart, and narrowing
of the arteries with exercise.
"It's not just a
matter of saying if you do enough tests you'll find something," Lipshultz
said. "Patients who got radiation to the heart (during childhood) really
need to be getting regular cardiac screening for all these types of problems."
Family doctors also need to be aware of these findings, Lipshultz said,
because it could affect the way they treat these patients in certain circumstances.
A childhood cancer survivor who got these treatments may need to be monitored
more closely during pregnancy, for instance, or when starting an exercise
regimen. "If they have a heart impairment, it's important to know that
because they could develop problems," Lipshultz said.
[Back]
FDA
OKs Treatment for Blood Cancer-(AP-14/05/2003)
The government has
approved a novel cancer treatment for one of the hardest-to-treat malignancies,
rushing the drug Velcade to multiple myeloma patients in hopes it will
buy them some time. Scientists hope Velcade, or similar drugs, could one
day become effective for other cancers. The drug is the first anticancer
proteasome inhibitor, meaning it targets an enzyme key to cell growth.
Uncontrolled cell growth is cancer's hallmark. The idea: Inhibit proteasome
action, and chemicals that control cell growth should be disrupted enough
for cancer cells to die. Velcade maker Millennium Pharmaceuticals first
tried the approach to treat multiple myeloma, a usually fatal blood cancer
that strikes 14,600 Americans a year. The condition is treatable but incurable,
and patients eventually run out of options. Half die within five years
of diagnosis.
Velcade isn't a cure
either, but studies suggest it can help a fraction of patients who have
exhausted other alternatives, the Food and Drug Administration ruled.
The FDA approved Velcade's sale less than four months after Millennium
filed its application, under a special program that lets promising drugs
for life-threatening illnesses sell before there's final proof of how
well they work. Millennium gave Velcade injections to 188 patients who
had relapsed despite about six prior therapies. Some 28 percent improved,
and that improvement lasted a median of one year - a surprising length
of time for people so sick, the FDA said. The FDA is requiring Cambridge,
Mass.-based Millennium to do further research to prove if that response
actually translates into living longer. But it's a response not seen with
standard chemotherapy for this cancer, "so this was impressive," said
Dr. Ann Farrell, who led FDA's review. Evidence so far suggests "this
represents a true advance over existing therapies," added FDA oncology
chief Dr. Richard Pazdur.
Normal cells contain
proteasome, too, making them vulnerable to the drug. Side effects include
many typical of chemotherapy: nausea, fatigue, diarrhea, constipation,
headache, decreased appetite, decreased blood cell production, and a nerve
damage called peripheral neuropathy. Still, for some unknown reason, Velcade,
known chemically as bortezomib, appeared more likely to select myeloma
cells, Farrell said. Millennium plans to begin shipping Velcade by month's
end. It will cost about $20,000 per average course of treatment - 16 to
17 weeks - which is comparable to other injected cancer therapies, according
to Barry Greene, the company's general manager in charge of oncology.
Millennium is studying whether Velcade also could treat advanced colon
and lung cancer.
[Back]
African
Milkbush Plant May Cause Childhood Cancer-(Reuters-13/05/2003)
A plant used in
Africa to make glue and herbal remedies may be an important cause of the
most common childhood cancer in Africa, scientists said on Tuesday. Children
use the sap from the milkbush plant to make toys, but researchers believe
exposure to the sticky liquid may make them more susceptible to the effects
of a virus that causes Burkitt's lymphoma, a tumor of the immune system.
"It is a critical clue to what might be driving the high frequency of
Burkitt's lymphoma in Africa. It also gives us an idea of how we can begin
working on preventing the cancer in the children as well," Dr. Rosemary
Rochford, of the School of Public Hygiene at the University of Michigan,
said in an interview.
The milkbush is common
in countries like Kenya and Tanzania, where it is grown as fencing and
used in medicines. Children also use it to make toys. But Rochford and
her team found evidence that children may unknowingly be putting themselves
in danger. When they studied the impact of the sap on the virus in the
laboratory, they discovered low concentrations switched on three genes
that were important in various stages of the virus, allowing it to replicate,
kill cells and infect new ones. Their research is reported in the British
Journal of Cancer. Burkitt's lymphoma is a very aggressive disease that
has been linked to the Epstein-Barr virus. Although children are most
affected by the disease, adults can also develop it. It is usually treated
with chemotherapy.
Scientists had previously
noticed that illness rates are higher in areas of Africa where the milkbush
is more common. "Burkitt's lymphoma is found in western countries, as
well as Africa, but you never see it in the jaw in western countries,"
Rochford explained. She suspects that while playing with the sap children
might be putting their hands to the face and absorbing it into the mouth
and stomach. Educating parents and children about the dangers of the milkbush
could help to prevent the cancer, Rochford added. "Further research is
necessary to confirm the link between exposure to milkbush sap and Burkitt's
lymphoma. But this study could be important if avoiding exposure to the
plant reduced the number of children suffering from the disease," said
Sir Paul Nurse of the British charity Cancer Research UK.
[Back]
Cancer
Said Side Effect of Gene Therapy-(AP-04/05/2003)
A revolutionary gene
therapy treatment that cured 10 French boys of a deadly inherited disorder
known as "bubble boy disease" gave two of them leukemia, scientists said.
Dr. Salima Hacien-Bey-Abina said genetic tests have confirmed that the
treatment, the first time that gene therapy has cured a disease, triggered
the cancer in the toddlers. The boys are responding well to anticancer
therapies, she added. Experts said it is now clear that the virus used
to carry the needed gene into the children's bodies landed in a bad place.
Scientists had always feared that cancer might occur if the virus used
in the therapy lodged near certain genes that control cell growth and
affected those too.
Addressing a conference
of the European Society of Human Genetics, Hacien-Bey-Abina of the Necker
Hospital for Sick Children in Paris said tests have shown that in the
first toddler stricken with leukemia, the correcting gene landed inside
a cancer-promoting gene called LMO-2. In the second toddler, the gene
landed near the LMO-2 gene. "Apart from the tragedy of those two kids,
I think this has put an enormous skid under a great deal of gene therapy,
on this whole business of using retrovirus vectors" to get the needed
genes into the body, said Andrew Read, a professor of genetics at Manchester
University and chair of the scientific committee for the conference. "That
is a perfectly general problem of retroviral vectors and not a problem
of the particular virus they used or the particular disease they treated
and I cannot see how in principle you can get rid of that risk," said
Read, who was not involved in the research.
The boys were given
the treatment starting in 1999 when they were babies, ranging in age from
one month to 11 months. The first toddler who developed leukemia appeared
healthy until August last year - 30 months after treatment - when scientists
found leukemia-like overproduction of white blood cells. After that finding,
the United States suspended its three gene therapy studies for the disorder.
A second child then developed leukemia in December, 34 months after getting
the therapy, Hacien-Bey-Abina said. The boys were born with severe combined
immunodeficiency, or SCID, a rare inherited disease that occurs in about
1 in 75,000 births. The best known victim was David, Houston's famous
"bubble boy" who lived in a germ-proof plastic enclosure until his death
at age 12 in 1984.
The French boys had
X-linked SCID, a severe form that strikes only boys. It is the most common
form of SCID, accounting for about half of cases. The disease involves
a genetic mutation that leaves them without certain proteins crucial to
developing disease-fighting immune cells. Without treatment, sufferers
die very young. Many babies with the disorder are saved with bone marrow
transplants, but they need monthly infusions of immune globulin, antibodies
culled from donated blood, for the rest of their lives. To reverse the
defect, doctors at Necker Hospital drew bone marrow from the boys. They
mixed specific stem cells from the marrow with a harmless virus in which
a gene that makes the missing protein had been inserted. They injected
the reconstituted cells back into the boys, giving them a working immune
system. "All the patients except patient four and patient five are doing
well. They are healthy and they are at home," Hacien-Bey-Abina said. She
said that one of the problems might have been the two boys who developed
leukemia were the youngest in the group when they received the treatment.
One was a month old, while the other was three months old. She theorized
that their stem cells were possibly too immature. Also, while the average
number of reconstituted cells injected back into the boys was 9 million
cells per kilogram of body weight, "the two patients who developed leukemia
received a particularly high number of transduced cells, around 20 million,"
Hacien-Bey-Abina told the audience.
Hacien-Bey-Abina
proposed that one possible way around the problem is to incorporate into
the virus a so-called suicide gene, which would abort the treatment if
things go wrong. Another way would be to build in a buffer zone around
the virus to diminish its effect on nearby genes. Even if such approaches
don't work, Read said, it doesn't mean that the therapy should never be
offered to children suffering from X-SCID. "In a disease like SCID, where
you know the kid is going to die if you can't give them a bone marrow
transplant, then if we're really talking about a one in four risk of leukemia
and the leukemia is treatable, maybe the risk is worth taking," Read said.
"But it's certainly not worth thinking about for more trivial conditions."
[Back]
Can
Genetic Research Yield Cancer Cure?-(HealthScoutNews-11/04/2003)
They call it the
genetics of cancer, and researchers predict that one day it may lead to
a cure. The approach has already hinted at a number of potentially remarkable
advances, such as creating individualized -- even painless -- treatments,
and finding the shared genetic characteristics between such diseases as
lung, colon and breast cancer. While this may sound like science fiction,
research in cancer genetics is already yielding dividends. The recent
development of the highly effective leukemia drug Gleevec is considered
a milestone because it targets cancer cells, while leaving healthy tissue
intact and causing few side effects, oncologists note. Gleevec is used
to treat chronic myeloid leukemia. However, it has spawned a new class
of "targeted-therapy" drugs, and is being tested on other cancers as well,
such as pediatric bone cancer. "For the first time, cancer researchers
now have the necessary tools to probe the molecular anatomy of tumor cells
in search of cancer-causing proteins," Dr. Richard Klausner, director
of the National Cancer Institute, says of Gleevec, which was approved
two years ago by the U.S. Food and Drug Administration.
The basic method
of developing drugs like Gleevec is fairly simple: isolate the genetic
markers of cancer to find the ones that trigger the tumor. Then test various
drugs against those trigger genes to see how they react. As a possible
side benefit, the data collected through the process may one day illuminate
genetic links between cancers. "It may not be that all cancers can boil
down to a certain gene, but it may be that certain sets of cancers, such
as skin cancer, have shared characteristics," says Dr. Peter Maslak, chief
of the hematology laboratory at the Memorial Sloan-Kettering Cancer Center
in New York City. "There's a tremendous amount of hope that within five
or 10 years we're going to understand the genetics of most cancers," adds
Dr. Len Lichtenfeld, with the American Cancer Society's science department.
But with April designated
as Cancer Control Month, Lichtenfeld emphasizes the best cure for cancer
remains prevention. "Clearly there are a lot of new technologies and approaches,
and a lot of them can help. But when we look at the big picture, what
we can do right now is focus more on smoking, exercise and nutrition,"
he says. More than 1.3 million Americans are expected to get cancer this
year, according to the American Cancer Society. Due to an aging population,
the number is rising despite declines in deaths from the four main cancers
-- lung, colon, breast and prostate. About two-thirds of all cancers,
however, could have been prevented based on lifestyle choices, Lichtenfeld
says. "There are huge returns in getting people to be healthy, stopping
smoking and getting regular screenings," he says.
There have also been
major advances in cancer detection. The use of molecular testing, for
instance, now allows doctors to find the smallest amounts of cancer in
a person's body. Although this helps doctors to monitor cancer patients
in remission to ensure the disease doesn't come back, it may also help
detect cancer earlier in seemingly healthy people. Traditionally, doctors
had used microscopes to detect cancer cells. But this technology is inexact
by today's standards, says Dr. Jerald Radich, a researcher with the Fred
Hutchinson Cancer Research Center in Seattle. Using a microscope, cancer
cells aren't visible unless there are lots of them -- about one tumor
cell to 100 healthy cells. Molecular testing, by contrast, can find one
tumor cell in a million healthy cells, leading to earlier detection and
treatment, Radich says.
Many of the advances
in cancer treatment result from research on leukemia. The reason is fairly
simple, Radich says. Because leukemia resides in the blood, it is easier
to extract and study than cancers that reside in tissue. Leukemia research
gained momentum in the 1970s, while research on other cancers lagged behind,
he says. But once researchers unlock the secrets of other cancer genes,
a new set of questions may arise, Lichtenfeld says. For example, as targeted
drugs become more refined, they may also become prohibitively expensive
to develop. Lichtenfeld is also concerned that use of new therapies might
outpace safety testing. A few years ago, for example, doctors thought
bone marrow transplants might help women with breast cancer, but it wasn't
until many of them had gone through this painful procedure that tests
showed it didn't really help, he says. "Hand-in-hand with all of this
wonderful technology is the question how to use it. If you don't concentrate
on how to use it early on, you may have to play catch-up for many years.
You don't want it used haphazardly," Lichtenfeld says.
[Back]
Prozac
Kills Burkitt's Lymphoma Cells: Scientists-(Reuters Health-15/04/2003)
British scientists
said that early lab research suggests Prozac and similar antidepressants
could treat at least one form of the cancer lymphoma. The University of
Birmingham team said they had discovered that, in the test tube, the drugs
could make Burkitt's lymphoma tumor cells commit suicide. Burkitt's lymphoma
is a fast-growing cancer that makes up only a small percentage of all |