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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
lymphomas, but is common in Africa. The drugs tested all belong to a class
of anti-depressants called selective serotonin reuptake inhibitors (SSRIs).
"The drugs activate the signaling mechanism that leads to the apoptosis
(suicide) program. The end results is that within 24 hours the cells are
dead," John Gordon, professor of immunology told Reuters Health.
Last year the same
team reported that the brain chemical serotonin activates the suicide
program and that SSRI drugs can block the entry of serotonin, thereby
protecting cancer cells. But the latest findings, published in the American
journal Blood, show that by increasing the quantity of the drug they could
reverse this process, forcing the cells to commit suicide. Gordon said
in a statement: "This new development is very exciting. We were intrigued
as to the impact of the SSRIs on the cancer and found that by increasing
the dosage of SSRIs the Burkitt's cells are killed. "The initial indicators
are exceedingly positive and we are already discussing with clinicians
about using these drugs as a therapy for Burkitt's lymphoma. We are now
examining the effect the SSRIs have on other cancer types."
Neuropharmacologist
Nicholas Barnes said the SSRIs were associated with very few side effects,
even when used at high dosages. "It should therefore be possible to determine
whether our research has direct clinical benefit with the minimum of delay."
At present, Burkitt's lymphoma is treated with chemotherapy, which generally
achieves a high cure rate. However, the scientist said response rates
in the case of AIDS-related Burkitt's lymphoma are much lower. "Furthermore,
the combination of chemotherapy, and the clinical support required is
not always readily available in underdeveloped countries where the disease
is endemic," the researcher said.
Britain's Leukemia
Research Fund said: "Burkitt's lymphoma is a particularly aggressive form
of cancer which affects a huge number of people in Africa and a significant
number of people in the UK. "While there is still some way to go before
doctors can start prescribing these drugs to patients with this cancer,
these findings could be of major importance to those patients with the
AIDS-related form of the disease, and to those patients who are not in
a position to tolerate the intensive chemotherapy. "Alternative treatments
such as this which are inexpensive and have low levels of toxicity would
be a major step forward in the treatment of this disease." A spokesman
for Eli Lilly, which makes Prozac, said the company was not involved in
the latest research. The drug -- once the company's biggest earner --
no longer has patent protection.
[Back]
Breastfeeding
May Not Cut Childhood Cancer Risk-(Reuters Health-08/04/2003)
British scientists
have found no evidence that breastfeeding protects children against leukemia
and other cancers, contradicting earlier research. Two years ago, the
UK Childhood Cancer Study found what researchers called "weak evidence,
of borderline statistical significance," that breastfeeding reduced childhood
cancer risks. Other researchers in the United States and elsewhere have
reported similar findings. But in the British Journal of Cancer, Drs.
Tom Sorahan and Robert J. Lancashire from the University of Birmingham
report data from more than 7,000 children in the Oxford Survey of Childhood
Cancers (OSCC) that throws these earlier studies into question. "The bottom
line of this report is that there was no suggestion of an association
between childhood cancer risk and breastfeeding," Sorahan told Reuters
Health.
The researchers used
surveys of 3,376 mothers with children who died of cancer between 1972
and 1981, and compared them with the same number of mothers with healthy
children. The children were matched for gender and date of birth. Their
results showed no indication that breastfeeding for any length of time
-- from less than one month to more than seven months -- reduced the risk
of any cancer type. "In my view, this leaves the topic in limbo," Sorahan
said. "The recent (UK Childhood Cancer) study has the advantage of including
incident cancers, whereas my study (the OSCC) only comprised cancer deaths."
However, his team's work has an advantage in its "historical" approach,
Sorahan added. "I would tend to put more reliance on interview data collected
many years ago," he said, "because people are now more aware of what they
'should be doing' (regarding breastfeeding), and might not be so honest
with their responses."
[Back]
Lymph
cancer vaccine may be near-(Yahoo News-14/03/2003)
A new Norwegian study
has determined that lymph cancer cells contain special molecules which
can be recognized by the immune system, the Norwegian Cancer Society reports.
This property could be exploited to kill malignant cells. The study, headed
by Dr. Alexander Fosså on a NCS scholarship, was carried out at the Immunology
Section of the Norwegian Radium Hospital. The discovery would allow the
immune system to identify the molecules and target cancer cells, making
a vaccine to fight lymph cancer a distinct possibility.
"Lymph cancer patients
who receive a portion of the molecules from cancer cells will have their
immune systems stimulated to aggressively attack cells bearing this molecule,"
Fosså explained to web site www.kreft.no. Current vaccine strategies must
be adapted to each patient, a time-consuming and expensive procedure.
The molecules identified by Fosså differ so markedly from others in the
body that they are readily identified as foreign bodies.
[Back]
Gleevec
New Gold Standard for Chronic Myeloid Leukemia-(HealthScoutNews-12/03/2003)
Gleevec has swept
aside interferon-alfa combination therapy as the drug of choice for newly
diagnosed chronic myeloid leukemia (CML). The results of a 16-country
trial that compared the two treatments appears in The New England Journal
of Medicine. The trial prompted the U.S. Food and Drug Administration
(FDA) to approve Gleevec for newly diagnosed CML in December. Previously,
the drug had been approved for advanced stages of CML and as a second-line
treatment for earlier-stage disease, if interferon-alfa plus low-dose
cytarabine, the old gold standard, failed. "We compared Gleevec to the
standard of care and, by all parameters, Gleevec is better," says Dr.
Hagop Kantarjian, a co-investigator on the study and chairman of the leukemia
department at M.D. Anderson Cancer Center in Houston. "Gleevec is a major,
major discovery.""It
doesn't mean it's a complete fix, but there's no question that Gleevec
is . . . better [than interferon therapy] and may well cure a whole bunch
of patients," says Dr. Samuel Kopel, associate director of hematology/oncology
at Maimonides Medical Center in New York City.
Currently, the only
cure for CML, which affects just under 15,000 Americans, is a bone marrow
transplant. But that's only an option for about 25 percent of the people
who develop the disease, and it carries with it considerable risks. People
with chronic CML, which is the first stage of the disease, produce too
many mature white blood cells (the cells that normally fight infection).
This stage progresses slowly and can last indefinitely. In the acute phase,
too many immature "blasts" are produced. In a normal person, blasts give
rise to a certain type of white blood cells. This acute or "blast-crisis"
phase is when most patients die.
The leukocytes or
cancer cells in people with CML have a genetic flaw called the Philadelphia
chromosome. This irregularity produces an abnormal protein, which in turn
produces a signal that pushes the cells into overdrive. "They reproduce
more than they should, they live longer than they should and they suppress
normal cells," Kantarjian says. Gleevec works by going inside the abnormal
protein and activating it in such a way that it can no longer send these
"bad" signals. "It's a very targeted kind of treatment," Kantarjian says.
Previous studies
showed that Gleevec was safe and effective and led to its approval by
the FDA in May 2001. What was missing was a direct comparison with existing
treatments so physicians would know where to place it within the hierarchy
of treatments. "The patients were telling the medical community that this
it was a great therapy and that they felt much better," says Alan Kinniburgh,
vice president of research at the Leukemia & Lymphoma Society. "What needed
to be shown in a head-to-head comparison was if it was medically better."
To that end, researchers randomly assigned 1,106 patients to receive either
Gleevec (553 patients) or interferon alfa plus low-dose cytarabine (553
patients). The study involved 177 hospitals in 16 countries. Participants
were followed for a median of 19 months, and different responses to the
drugs were evaluated. In the end, Gleevec appeared to rank higher in two
basic and important ways: People on the drug lived longer without progressing
to the next phase, and more people taking Gleevec had a reduction in the
number of Philadelphia chromosomes in their blood cells. After 18 months,
87.1 percent of patients in the Gleevec group versus only 34.7 percent
in the other group had a "major cytogenetic response," meaning that no
more than 35 percent of the cells tested positive for the Philadelphia
chromosome. The authors estimated that 76.2 percent of patients in the
Gleevec group, vs. 14.5 percent of the others, had the Philadelphia chromosome
completely wiped out. At the end of one year, 96.6 percent of patients
in the Gleevec group had not progressed to the acute phase of the disease,
compared with 79.9 percent of patients in the other group. At 18 months,
92.1 percent and 73.5 percent of the participants, respectively, had not
progressed. Overall, however, the estimated survival rates were roughly
equivalent -- 97.2 percent in the Gleevec arm and 95.1 percent in the
combination-therapy. But that's probably because almost 90 percent of
the patients in the interferon arm switched to Gleevec before the study
concluded. Only 14.3 percent of the patients in the Gleevec group crossed
over to interferon.
This no doubt had
to do with side effects. According to Kantarjian, only 2 percent of patients
on Gleevec had severe side effects, versus 30 percent or more on interferon.
"It felt like night and day," says John Shaw, 42, a New York City actuary
who was diagnosed with CML in 1998 and who tried interferon before joining
the Gleevec trial. With an interferon combination, he adds, "I had a lot
more fatigue. My concentration ability was a lot less and I didn't have
as much strength as I do now. Once I went off interferon and started taking
Gleevec, there was a complete difference. I feel normal again." Shaw went
on Gleevec in March of 2001 and by June was in complete remission. The
overall picture for people diagnosed with CML has improved drastically.
"In the past when we saw patients with CML, we quoted them an average
survival of three years. With interferon, that increased to about six
years," Kantarjian says. "Now, with Gleevec, the average survival will
go beyond 10 years and we may be able to get rid of the disease completely
in at least 40 to 50 percent of patients, which in the long run is the
potential for a cure," he adds.
[Back]
Patient's
Cancer Cells May Help Treat Non-Hodgkin's Lymphoma-(ET-05/01/2003)
The type of cancer
that took the lives of Jacqueline Kennedy Onassis and King Hussein of
Jordan may yield clues about how to train a patient's own immune system
to kill malignant tumors. Ongoing research trials are targeting non-Hodgkin's
lymphoma as one of the first cancers that might be treated through personalized
vaccines - if they can prove a shot against cancer is effective.
Non-Hodgkin's lymphoma,
a malignancy of white blood cells, is the sixth most common cancer in
the United States. For mostly unknown reasons, its incidence in the United
States has nearly doubled since the early 1970s, especially among the
elderly. It commonly resists standard treatments such as chemotherapy.
[Back]
Another
Advancement for Leukemia Drug-(HealthScout News-22/12/2002)
Gleevec, a drug that
showed significant results in combating a rare and mostly fatal type of
leukemia, has passed another hurdle. The U.S. Food and Drug Administration
has announced that Gleevec (imatinib mesylate) has been approved for the
"first-line treatment of patients with chronic myeloid leukemia (CML),
an uncommon life-threatening form of cancer -- affecting about 40,000
people in the United States."
First-line treatment
means that Gleevec can be administered after CML has been diagnosed. The
drug was originally approved in 2001 under the FDA's accelerated approval
regulations.The federal agency believed more time was needed to determine
whether Gleevec would continue to be as effective in arresting the leukemia
as it had been when it was used after other drugs had been tried. "Today's
approval represents continued efforts by government and industry to provide
patients suffering from CML with additional therapies that have proven
safe and effective through on-going research and clinical trials," said
FDA Commissioner Dr. Mark B. McClellan. "With this new use, even more
patients will have access to this product earlier on in their fight against
cancer," he said in an FDA press release.
Approval was based
on a clinical trial of 1,106 patients with newly diagnosed chronic phase
CML, according to the FDA. Half were given Gleevec and half were given
a standard drug therapy. The results: The patients treated with Gleevec
after one year had significantly fewer cancerous cells in their blood
and bone marrow. The rate of progression of disease was also decreased
in the patients treated with Gleevec, according to the FDA.
[Back]
New
Stem Cell Technique for Leukemia Treatment (Reuters-28/10/2002)
British scientists
have developed a new stem cell technique that could help patients with
advanced leukemia or lymphoma. They genetically tinkered with donor stem
cells -- master cells that can develop into virtually any cell type --
so that they can survive highly toxic chemotherapy. Raj Chopra, a doctor
at the University of Manchester, who developed the technique, told a cancer
conference that preliminary results from early animal studies were encouraging.
"Our new system, which we call genetic chemoprotection, prevents donor
stem cells from being harmed by chemotherapy and so should allow us to
use much higher doses than would otherwise be possible," Chopra explained.
Stem cell transplants
may be used to treat leukemia and lymphoma, cancers of the blood and the
lymphatic system that have not responded to normal therapy. Donor stem
cells are transplanted into the patient to produce an immune response
against the disease. It is often followed by high-dose chemotherapy to
kill the cancerous cells but the toxic drugs can also harm the donor stem
cells. In an effort to overcome the problem, Chopra and his colleague
Dr Lez Fairbairn isolated stem cells, grew them in the laboratory, and
used a virus to insert a gene, called Atase, to make them resistant to
the toxic effect of the chemotherapy drugs. In a study on mice, the chemotherapy
drugs killed the cancerous cells and many of the animals' own stem cells
but the transplanted donor cells survived and strengthened the animal's
natural anti-cancer immune system. The immune system response increased
with the proportion of donated stem cells and the transplanted cells multiplied
and filled in the gaps left by the destroyed natural stem cells.
"The immune response
is entirely generated by the cells we've transplanted," Chopra told a
meeting of the medical charity Cancer Research UK. Although it is still
very early days and human trials of the technique are still many years
away, Chopra said the treatment could potentially make treatments doubly
effective. Stem cells, which are derived from embryos, fetuses, umbilical
cords or from a patient's own tissue, have the potential of curing diseases
such as diabetes, stroke, heart disease, Alzheimer's and some types of
cancer. But their use is highly controversial because the most promising
stem cells are derived from human embryos.
[Back]
Caution
Recommended in Epoetin Use for Anemia in Hematologic Malignancy (Reuters
Health-24/10/2002)
For anemic patients
with hematological malignancies, conventional therapy should be tried
before using epoetin, according to new practice guidelines from the American
Society of Clinical Oncology and the American Society of Hematology. Under
the auspices of both societies, Dr. J. Douglas Rizzo from the Medical
College of Wisconsin, Milwaukee, and colleagues developed an evidence-based
guideline for using epoetin in anemic cancer patients. The guidelines
are published in the Journal of Clinical Oncology.
The guideline panel
recommends epoetin as a treatment option in patients with chemotherapy-related
anemia whose hemoglobin level is less than 10 g/dL. In patients with less
severe anemia, clinical circumstances should determine epoetin use, they
add. Dr. Rizzo's group notes that evidence from clinical trials supports
giving epoetin subcutaneously three times per week at doses of 150 U/kg
for at least 4 weeks. They also recommend increasing the dose for patients
who do not respond to initial therapy. When there is no response, treatment
should not be continued beyond 6 to 8 weeks, they note. Epoetin should
be titrated when hemoglobin levels reach 12 g/dL, they add. "Evidence
from one randomized controlled trial supports use of epoetin for patients
with anemia associated with low-risk myelodysplasia not receiving chemotherapy;
however there are no published high-quality studies to support its use
for anemia in other hematologic malignancies in the absence of chemotherapy,"
Dr. Rizzo's team comments. Dr. Rizzo and colleagues conclude that "for
anemic patients with hematologic malignancies, it is recommended that
physicians initiate conventional therapy and observe hematologic response
before considering use of epoetin."
[Back]
'Cocktail'
Could Combat Leukemia (HealthScoutNews-21/10/2002)
A new cancer-killing
"cocktail" shows promise in laboratory studies as an effective way to
attack acute myeloid leukemia (AML), a cancer of the blood. A team led
by Dr. Edward D. Ball, director of the Blood and Marrow Transplantation
Program at the University of California-San Diego School of Medicine,
report the findings in the Biology of Blood and Marrow Transplantation.
The researchers took
blood samples from 12 patients, either diagnosed or just relapsed with
AML. They separated out the white cells, which included AML cells and
T-lymphocytes, the family of cells that mount an immune response to infected
or cancerous cells. To the mix, they added growth factors and interleukin-4
-- which helps activate the immune system -- to turn the lymphocytes into
stronger fighters. "We induced them to change into dendritic cells, which
are better able to induce immunity or immune response from T-cells," Ball
says. "At the end of the 40-day culture, we had a pure culture of T-cells.
Almost all the leukemia cells were gone."
The work is at the
laboratory stage, Ball cautions, and he must prove the cancer cocktail
works in animals and in humans before it can become available. The long-term
hope, of course, is to have the cancer "cocktail" be a cure. About 10,600
new cases of AML are diagnosed each year, according to the Leukemia &
Lymphoma Society. AML is also called by other names, including acute myelogenous
leukemia and acute myelocytic leukemia. Patients often feel a loss of
well-being and complain of fatigue. They may notice bruises after minor
injuries and have fever, swollen gums, and slow healing of cuts. Currently,
Ball says, "we're pretty good at getting people into remission. But over
50 percent relapse. And when they relapse, they start to develop chemotherapy
resistance." Bone marrow transplant is another treatment option, he says,
but even then "a fair number will relapse after transplant."
Other experts familiar
with the study offer praise. "It's a very interesting lab study that may
be useful as a treatment for people with AML," says Alan Kinniburgh, vice
president of research for the Leukemia & Lymphoma Society. "It's very
preliminary. The results need to be confirmed in another lab. And we need
to see if it works in people. We'll have to wait to see whether the cells
can be reintroduced successfully [back into people]." The latest study
extends the possibility that immunotherapy might be effective, says Dr.
Stephen Forman, director of the hemotologic neoplasia program at the City
of Hope Cancer Center in Duarte, Calif. "What Dr. Ball's approach does
is take a series of growth factors and stimulate them in culture to generate
cells from a patient's own blood that will recognize leukemia and kill
it," he says.
[Back]
Wine
Drinking Linked to Lower Lymphoma Risk (Reuters Health-16/09/2002)
Men who consume moderate
amounts of wine on a regular basis seem to have a reduced chance of developing
non-Hodgkin's lymphoma, researchers report. However, it is not clear if
the wine itself--or some other lifestyle-related factor--is responsible
for the risk reduction.
Non-Hodgkin's lymphoma
refers to several types of cancer that start in the lymphatic system but
often spread throughout the body. It is the fifth most common cause of
cancer in the US, according to the study's lead author Dr. Nathaniel C.
Briggs of Meharry Medical College in Nashville, Tennessee. Although a
weakened immune system and exposure to certain chemicals on the job are
linked to non-Hodgkin's lymphoma, overall risk factors for the disease
are "obscure," Briggs told Reuters Health. "Because so few risk factors
have been identified, efforts to prevent non-Hodgkin's lymphoma need to
take protective factors into consideration," added Briggs. While several
studies have found that wine drinkers seem to be less likely to develop
the disease, the research is inconclusive.
In a new study,
Briggs and colleagues looked at 960 men between the ages of 32 and 60
who were diagnosed with non-Hodgkin's lymphoma between 1984 and 1988.
They compared the men's lifestyle habits with 1,717 similarly aged men
who were cancer-free. The investigators found that men who regularly drank
an average of one or more glasses of wine daily, and who had been regular
drinkers--averaging one or more alcoholic beverages per week from the
time they were teenagers--had a more than threefold decrease in non-Hodgkin's
lymphoma risk compared with nondrinkers, Briggs explained. Among wine
drinkers who started drinking at older ages, the protective effect against
non-Hodgkin's lymphoma was less pronounced--a 30% reduction in non-Hodgkin's
lymphoma risk with consumption of one or more glass of wine daily, the
researcher added. There
was no link between consumption of beer or spirits and a higher or lower
risk for non-Hodgkin's lymphoma, according to the report in the American
Journal of Epidemiology.
Although wine drinkers
in the US tend to be wealthier than those who consume other types of beverages,
the researchers tried to take that into account by correcting for education.
However, there may have been other factors associated with higher income--such
as a healthier lifestyle in general--which could not be taken into account
because the researchers did not have that information. "In no way do we
endorse underage drinking," said Briggs. "In fact the absence of any protective
effect for consumption of beer or spirits suggests that alcohol itself
is not the protective factor."
Instead, Briggs noted
that a chemical called resveratrol, which is "a phytoestrogen produced
by grapes, and a natural ingredient in wine, has been shown to inhibit
the initiation, as well as promotion and progression of cancer." According
to Briggs, "If the association is real, non-toxic non-Hodgkin's lymphoma
prevention strategies might be possible, such as resveratrol-enriched
table grapes or grape jelly." Red wine has higher levels of resveratrol,
but the researchers did not determine if the men drank red or white wine,
or a combination of both. Briggs pointed out that the findings can't be
extrapolated to consumption of more than one glass of wine per day, because
there were too few heavier wine drinkers to investigate risk at higher
levels. And, Briggs noted that because the study population was restricted
to men, the findings may not be generalizable to women.
[Back]
FDA
Reviews Novartis Cancer Drug (AP-22/08/2002)
Novartis said that
its anti-cancer drug Gleevec is receiving a priority review from the U.S.
Food and Drug Administration for use by a wider range of sufferers. The
FDA took only three months to approve the drug for the treatment of adults
in the late-stages of chronic myeloid leukemia, or CML, and stomach cancer.
Now the Swiss pharmaceutical company has applied for approval of Gleevec
- known as Glivec outside the United States - for the treatment of children
and of newly diagnosed CML patients. The FDA grants priority reviews to
products for serious or life-threatening diseases that may offer a significant
improvement compared with existing therapies. "The current labeling represents
around 25 to 30 percent of patients suffering from chronic myeloid cancer,"
said David Epstein, head of Novartis' oncology unit. He said research
and trial data show that the earlier CML patients are treated with Gleevec,
the more likely they are to respond positively to the drug.
Currently, a bone
marrow transplant is the only known cure for CML. The standard treatment
is with interferon, which can extend a leukemia patient's life by up to
two years but can have side effects that cause about 20 percent of patients
to stop using it. Initial data showed that the treatment with Gleevec
is about three times more effective than today's standard treatment with
interferon, Epstein said. Novartis is developing a number of drugs that
work similarly to treat solid tumors found in colon, ovary or breast cancer,
metastatic colorectal cancer and iron overload, he said.
[Back]
DNA
Test Picks Up Lingering Leukemia in Kids (Reuters Health-05/08/2002)
A new test that
should allow doctors to fine-tune treatment for children with leukemia
is being evaluated in Britain, researchers said. Dr. Nick Goulden, from
Bristol Royal Hospital for Children, and colleagues in Glasgow, Leeds,
London and Sheffield, are using "real-time quantitative polymerase chain
reaction" (RQ-PRC) to measure the number of leukemia cells left after
a child with acute lymphoblastic leukemia (ALL) undergoes chemotherapy.
ALL is the most common form of leukemia, affecting 450 children each year
in the UK, or about 75% of all cases of childhood leukemia.
Children treated
for this cancer always have some leukemia cells remaining in their bone
marrow after the first month of chemotherapy, Goulden said. The level
can fluctuate between 1 in 20 cells to 1 in 10,000 cells, but conventional
techniques cannot accurately measure the levels. Improvements in treatment
for ALL over the last 30 years have raised survival rates to around 80%,
but aggressive chemotherapy has unpleasant side effects that may be unnecessary
for children with low numbers of residual cells, the researchers say.
"Preliminary studies have demonstrated that measuring residual disease
enables us to predict whether a child will relapse," Goulden said in a
statement. "We hope that once this test is established in the UK, doctors
will be able to intervene at an earlier stage with more or less aggressive
therapy based on the level of residual disease present in the blood and
bone marrow."
After the genetic
sequence of a leukemia cell has been identified, RQ-PCR allows scientists
to amplify the sequence millions of times within the space of a few hours.
Dr. David Grant, scientific director of the Leukemia Research Fund, said:
"This is a key step forward which should lead to better treatment for
every single child who is diagnosed with this terrible disease."
[Back]
Hepatitis
C Linked to Rare Lymphoma (HealthScoutNews-10/07/2002)
Treating a viral
infection can help some patients with a rare cancer of the immune system,
French researchers say in a finding that might sound esoteric but offers
a new way to fight many kinds of leukemia and lymphoma. The cancer is
splenetic lymphoma, a malignant overgrowth of the white cells the body
makes as a reaction to infection, and the infectious agent is hepatitis
C virus.
Seven of nine patients
with the lymphoma had complete remissions after they were given interferon
to fight the virus. Two other patients had the same remission when ribavirin,
another antiviral drug, was added to the treatment, says a report from
researchers at Necker Hospital in Paris. It appears in New England Journal
of Medicine. All those patients were given the antiviral drugs because
they tested positive for hepatitis C. Tellingly, six patients with the
same lymphoma who were not infected with hepatitis C were not helped by
antiviral treatment.
Why is such a small
trial interesting? Because it adds to the growing body of evidence that
an infection can trigger a cancer of the immune system, says Alan J. Kinniburgh,
vice president for research of the Leukemia and Lymphoma Society. "A virus
elicits a response of the immune system to fight the infection, and in
that process there is rapid division of white cells," Kinniburgh explains.
"There may be mistakes made in replicating those cells, and some of the
resulting cells have a growth advantage that continues and manifests itself
as these rare lymphomas. What this study points to is that these infectious
agents may be participating in other lymphoid diseases, such as chronic
lymphoid leukemia."
Both lymphomas and
leukemias are malignant overgrowths of white blood cells, Kinniburgh says.
"If the disease occurs in the blood and not in the lymph nodes, we call
it a leukemia," he says. "If it occurs in the lymph nodes, we call it
a lymphoma. This one occurs in the spleen, as well as the lymph nodes."
One prospect is to detect such a cancer in its early stages, he says:
"If we can recognize that this process is occurring, we could use antiviral
treatment to stop it. But that now is speculation. We need much more research
in this area."
A role for viruses
in leukemias and lymphomas was recognized as early as the 1960s, when
the Epstein-Barr virus was detected in a malignancy called Burkitt's lymphoma,
says an accompanying commentary by Dr. Joseph S. Pagano of the University
of North Carolina at Chapel Hill. Since then, more than half a dozen viruses
have been associated with different lymphomas, Pagano says, and the new
report "broadens our perspective." However, the picture is complex, Pagano
and Kinniburgh say. Many people are infected with the hepatitis C virus,
and very few of them develop lymphoma, and not everyone with a lymphoma
is infected with the virus, Kinniburgh says. In the French report, six
of 15 patients did not have the infection. However, looking for signs
of infection in patients with leukemia and lymphoma could lead to new
treatments, Pagano writes. "A holy grail in cancer is the discovery of
cellular markers that are distinct from those found in normal cells,"
he says. "Thus, virus-associated cancers that express viral neoantigens
serve as inviting targets for specific therapeutic interventions." "Larger
therapeutic trials of antiviral therapy are needed to determine the role
of antiviral therapy in hepatitis C virus-infected patients with low-grade
lymphoma," the French researchers write.
[Back]
Genetic
Testing May Help Predict Lymphoma Survival-(Reuters Health19/06/2002)
Genetic testing could
help predict how patients with a common form of lymphoma will respond
to chemotherapy, new research suggests. An international research team
has identified several genetic "signatures" that are related to the odds
of survival after chemotherapy among patients with diffuse large-B-cell
lymphoma, the most common type of adult lymphoma. The findings suggest
that genetic analysis of patients' tumors could point toward the best
treatment approach, according to the study authors. For example, a patient
deemed unlikely to be cured with chemotherapy might instead be offered
a bone marrow transplant as a first-line treatment, Dr. Louis M. Staudt
told Reuters Health.
Lymphomas are a group
of related cancers of the lymphatic system, a component of the immune
system that carries infection-fighting white blood cells. Because lymph
nodes and other lymph tissue exist throughout the body, lymphoma can arise
in or spread to a range of tissue. There are two major forms of the disease--Hodgkin's
and non-Hodgkin's lymphoma--and further subgroups. Diffuse large-B-cell
lymphoma accounts for roughly 40% of non-Hodgkin's lymphomas. About 2
years ago, Staudt and his colleagues used "molecular profiling" to identify
two distinct forms of diffuse large-B-cell lymphoma that showed different
responses to chemotherapy. In the new study, which involved tissue samples
from 240 patients, the researchers found a third, distinct subgroup of
the disease. Survival after chemotherapy differed among the groups, with
patients with the more-favorable form having a 5-year survival rate of
60%--compared with 35% and 39% for the other two forms, the report indicates.
Moreover, the researchers
found several patterns of gene expression in patients' tumors that further
separated higher- from lower-risk patients within the disease subgroups.
These genetic "signatures" were related to factors such as whether tumor
cells were dividing rapidly and how well a patient's immune system was
fighting the cancer. The team came up with 17 genes that could be used
to predict survival after chemotherapy. "We feel these 17 genes...can
be translated into a clinical test," Staudt said. However, genetic analysis
like that used in this study cannot account for all the factors that determine
a patient's treatment response, according to an editorial accompanying
the report. While the study is an "an important step forward," it remains
to be seen whether a predictive test based on the findings will advance
the treatment of diffuse large-B-cell lymphoma, writes Dr. Ian Magrath
of the International Network for Cancer Treatment and Research in Brussels,
Belgium. The editorialist adds, however, that "whatever the immediate
future," molecular profiling will aid in developing new, targeted cancer
drugs. Already, Staudt said, the NCI is planning a trial of combining
chemotherapy with a drug that specifically inhibits a molecular "pathway"
called NF-kappa B that is activated in one of the subgroups of large-B-cell
lymphoma that has a poor prognosis.
[Back]
Leukemia
Survivors Advised Not to Delay Motherhood-(Reuters-03/07/2002)
Women who have conquered
childhood leukemia should not put off having children for too long because
the cancer drugs they were given may have affected their fertility, said
Danish scientists. Even though they may have normal monthly cycles, their
ovaries may be producing fewer follicles and eggs, said Dr. Elisabeth
Larsen of the Fertility Clinic at Copenhagen University. "The new finding
is that female childhood cancer survivors with an apparently normal menstrual
cycle might have a shortened reproductive span," said Larsen. Although
it is not possible to estimate how much shorter the span might be, Larsen
said her hospital is advising childhood leukemia survivors to have their
first child before they are 30. "They should not postpone childbearing,
and it might be that they should consider becoming mothers before pursuing
a career," she said.
Advances in chemotherapy
drugs have increased the survival of children with childhood leukemia
but doctors are discovering they can produce late effects. Larsen and
her team studied 26 women who had treatment for childhood leukemia and
a control group of 20 healthy women. They found that the cancer survivors
had shorter monthly cycles and smaller ovaries and they produced fewer
follicles, which contain the egg, than the women who had never had cancer.
"Although these long-term survivors of childhood leukemia have an apparently
normal ovarian function, our results suggests that the chemotherapy has
reduced the numbers of follicles in the ovaries," said Larsen. She suggested
that childhood cancer survivors receive fertility counseling and be advised
that their fertility may be reduced because of the treatments they had
earlier. "The important message to come from this research is that women
who have survived acute lymphoblastic leukemia can become pregnant and
have babies and they are doing so," Larsen told the annual meeting of
the European Society of Human Reproduction and Embryology (ESHRE) here.
[Back]
British
Study Finds No Radon, Childhood Cancer Link (Reuters Health-11/06/2002)
Two recent studies
of households in England, Scotland and Wales suggest that high levels
of naturally-occurring radiation, such as radon, do not translate into
a greater risk of cancer in children who live in those homes. The researchers,
who published their studies in the British Journal of Cancer, said there
has been some suggestion from previous studies that radon and cosmic or
ground radiation might contribute to childhood cancers such as leukemia
and lymphoma. But their results showed otherwise. "Although some areas
have higher levels of radon or gamma radiation than others, the differences
don't seem to be big enough to produce a detectable effect," said Sir
Richard Doll, a professor at the University of Oxford, and chairman of
the UK Childhood Cancer Study group that conducted the research.
In the first study,
the scientists compared radon measurements from the bedrooms and living
rooms of 2,226 children who had cancer with those from homes of 3,773
children who were healthy. Higher radon levels did not seem to play any
role in promoting six different cancers, including acute lymphoblastic
leukemia and other leukemias, non-Hodgkin's lymphoma, Hodgkin's disease,
central nervous system tumors and other solid tumors. In fact, the researchers
found that increasing radon levels were associated with lower cancer rates.
But they said they aren't sure why. Not surprisingly, there were higher
radon readings in wealthier homes, which tend to have double-glazed windows,
central heating, and other amenities that keep houses more airtight. But
the cancer rates were no higher or lower for those homes.
The authors said
that even though they may not have gotten accurate average radon readings--levels
vary with the season---the levels they did measure "offer no support for
the suggestion that radon concentration is associated with the incidence
of childhood cancer in general, or of leukemia in particular." In the
second study, a detector was used to measure natural gamma ray radiation
in the homes of 2,165 children with cancer and 5,086 homes of healthy
children, for 5 to 7 months. Based on the results, "there is no suggestion
of either an increasing or decreasing risk from any of the groups," said
the authors. There has been scant suggestion that natural radiation from
outer space or the ground might contribute to childhood cancer, but it
has been a worry of British parents, according to Doll.
Alan Kinniburgh,
vice president of research of The Leukemia & Lymphoma Society in White
Plains, New York, said that it is reassuring to know that radon and background
radiation may not be linked to these types of cancers, but the results
are not surprising, since they are viewed as unlikely contributors. Rates
of leukemia, lymphoma and brain cancer in children are very low, he said,
noting that there are only about 2,400 new childhood leukemias each year
in the US. The likely cause in most cases seems to be gene transcription
errors, not environmental factors, he said. Radon is a naturally occurring
gas that seeps into buildings from the surrounding soil. A person is unable
to see or smell radon gas and the only way to know if a problem exists
is to test for it. Long-term exposure is known to increase the risk of
lung cancer in adults, particularly in smokers.
[Back]
Major
Improvement Found in Lymphoma Remission Trial (HealthScoutNews-17/06/2002)
Dramatic results
from an experiment with people suffering from a form of lymphoma are demonstrating
an extended remission rate where none existed before. High-dose radioimmunotherapy
(RIT) offers long-term remission for people with mantle cell lymphoma,
according to research presented at the Society of Nuclear Medicine's annual
meeting in Los Angeles. Mantle cell lymphoma is also known as a B-cell
lymphoma, an often-fatal form of Non-Hodgkin's Lymphoma.
About 1,300 new cases
occur yearly in the United States. People with mantle cell lymphoma rarely
live more than three years after diagnosis. "Radioimmunotherapy is systemic
radiation therapy using monoclonal antibodies tagged with radioactive
isotopes that target tumor cells... radioimmunotherapy is used in treating
metastatic breast cancer, B-cell lymphomas, and prostate cancer that has
not responded to conventional hormone ablation therapy." The German study
presented today included 12 people with mantle cell lymphoma who had relapsed
after receiving high-dose chemotherapy. In the study, the people were
given either low-dose rituxan (an anti-lymphoma chemotherapy drug) with
RIT or a high-dose regimen of the same therapy. There was complete remission
in seven of the eight patients who received the high-dose RIT, compared
to only one of four people treated with low-dose RIT. The other patient
who received the high-dose RIT had a partial remission. After 42 months,
seven of the eight high-dose patients were still alive and six of them
were in complete remission, the researchers said.
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Gleevec
Helps Fight Leukemia Early On: Report -(Reuters Health-20/05/2002)
The novel cancer
drug Gleevec, already used to treat advanced stages of a bone marrow cancer
known as chronic myeloid leukemia, can also help prevent early stages
of the disease from advancing to the deadly phase better than conventional
treatment can, new research shows. "Based on this study, Gleevec should
now be considered the standard first-line therapy for chronic myeloid
leukemia," said study author Dr. Brian Druker of the Oregon Health and
Science University in Portland. "By all parameters measured, Gleevec was
significantly superior to (standard) interferon-based therapy," he said
at a meeting of the American Society of Clinical. Other experts agreed.
"The striking thing about this paper is that extremely few patients went
on to the blast crisis phase of leukemia," said ASCO president Dr. Larry
Norton, of Memorial Sloan-Kettering Cancer Center in New York. "This is
actually preventing the emergence of a disease that would otherwise be
much harder to treat."
The study compared
the effectiveness of Gleevec, also known as STI-571, to standard drug
therapy--interferon plus cytarabine--in 1,106 patients newly diagnosed
with chronic myeloid leukemia. After a median follow-up of 14 months,
68% of patients treated with Gleevec showed no signs of cancer, compared
with 7% of those in the interferon group, Druker reported. Gleevec was
"10 times more effective," he said. And just 1.5% of patients in the Gleevec
group developed the severe, deadly stages of the disease, compared with
7% of the other patients. Unlike other available cancer treatments, Gleevec
is unique in that it specifically targets cancer cells, sparing healthy
tissue and therefore causing fewer side effects.
The drug, made by
Novartis AG, is known as a tyrosine kinase inhibitor because it interferes
with an abnormal tyrosine kinase enzyme that promotes cancer growth. Gleevec
has been on the market since last May, when it was approved by the US
Food and Drug Administration for the treatment of advanced chronic myeloid
leukemia. In the new study, fewer than 1% of Gleevec patients had severe
side effects, compared with 23% of the other group. Druker said the worst
adverse reaction associated with Gleevec was severe swelling, known as
edema.
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Number
of Childhood Cancer Survivors Up Dramatically (HealthScoutNews-20/05/2002)
The number of children
who survive cancer has surged dramatically in the past three decades.
By one estimate, 75 percent to 80 percent of patients can now expect to
live five or more years, up from only 20 percent to 25 percent 30 years
ago. That statistic is one of the first major findings to be released
from an unprecedented study into the long-term health of childhood cancer
survivors. It was made public yesterday at the American Society of Clinical
Oncology meeting in Orlando, Fla. This encouraging news means aggressive
treatments pioneered in the 1970s are working, and working well. However,
it also means that, while doctors know the short-term effects of the drugs
used to treat young cancer patients, they have little idea what the long-term
health prospects are because past survival rates were so low. "It's become
so important to find out what is happening long-term with these kids so
we can adjust treatment for kids still coming along," says Dr. Stuart
Toledano, a professor of pediatrics and the head of pediatric oncology
at the University of Miami. "If we can't prevent the disease, at least
we want to give treatment that's not only effective but also the least
toxic. In addition, some treatments may have unforeseen effects as a person
ages."
For the Childhood
Cancer Survivor Study, researchers at 25 sites nationwide gathered information
from 14,000 young people who had had cancer between 1970 and 1986, before
they turned 21. The study, which began nine years ago, is funded primarily
by the National Cancer Institute. The study found the majority of survivors
over the age of 18 considered themselves to be in good general health,
with a quality of life comparable to anyone else.
However, the news
isn't all good on all fronts. Female cancer survivors were found to have
more problems with mental health, anxiety and physical activities. Also,
survivors of brain tumors, Hodgkin's disease, bone tumors and soft tissue
sarcomas seemed to be at the highest risk for health problems. There was
a significantly higher occurrence of pulmonary complications, including
lung fibrosis, emphysema and pneumonia, in cancer survivors. Radiation
and some forms of chemotherapy are known to have short-term adverse effects
on the lungs. The study confirms that damaging effects can also emerge
months and years after therapy, says lead investigator Leslie L. Robison,
a professor of pediatrics at the University of Minnesota Medical School.
Survivors of acute
lymphoblastic leukemia were much more likely to be obese or overweight
than their siblings, especially if they had received cranial radiation.
Cranial radiation has been a mainstay of leukemia therapy because it prevents
leukemia cells from entering the central nervous system, Robison says.
The long-term health implications of obesity are, of course, considerable.
"If you add that on to a patient or survivor who may have received chemotherapy,
which could damage the heart, we may be setting up a population of survivors
who are at an extremely high risk for cardiovascular events. If that's
the case, that group needs to be followed exceedingly closely."
Bone tumor survivors,
on the other hand, reported few difficulties, regardless of whether they
had had a limb amputated. "At this stage, analyses are suggesting that
[bone tumor] survivors don't show any difference in terms of physical
function, as well as quality-of-life perception," Robison says. This information
could help families and physicians when they're faced with the decision
of having to amputate or undergo a different procedure that involves its
own risk.
The just-released
results are the tip of the iceberg. The study will continue indefinitely,
while investigators research a whole spectrum of potential health drawbacks
from cancer treatments, including the possibility of premature menopause
and reduced fertility. Robison expects an average of 10 to 12 new scientific
studies to be published every year. The findings could be critical to
the well being of children who are only now being diagnosed with cancer.
Toledano tells the
story of a teen-aged boy he successfully treated for Hodgkin's disease
more than 10 years ago. Toledano kept in touch infrequently with the boy's
mother, learning when his former patient went to college, got married
and settled down with a good job. A year and a half ago, Toledano was
shocked to learn the young man had died of a massive heart attack at the
age of 30. The autopsy results showed he had extraordinarily severe thickening
of the arteries. In retrospect, Toledano says some of the chemotherapy
the boy received, as well as radiation, could have affected his heart.
Now, Toledano screens all his young adult patients for lipids, or fats,
and other indicators of heart disease. "You don't wait because the aging
process might occur much earlier," he says. "Those things you only gain
from long-term follow-up."
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Natural
Killer Cells May Improve Marrow Transplants-(Health Scout-14/03/2002)
Hiring the immune
system's hit molecules may help bone marrow transplant patients better
tolerate the grafts, and even fight the cancers they're designed to treat.
Leukemia patients who receive a marrow donation with the right kind of
"natural killer cells," which do just what their name suggests, are much
less likely to reject the grafts, according to a new studies by U.S. and
Italian researchers. Experiments in mice show the natural killer cells
also appear to help eradicate lingering leukemia. Better yet, targeting
an enzyme that seems to arouse them may make bone marrow grafts more palatable
to patients. The findings, reported in Science, could give doctors another
layer of screening for bone marrow recipients to improve their chances
of success.
"You can try to do
these tests before you do the transplant and find not just a well-matched
donor, but one whose natural killer cells will react against the patient's
leukemic cells," says Alan Kinniburgh, vice president of medical affairs
and research for the Leukemia and Lymphoma Society. William J. Murphy,
director of basic research at SAIC, a Maryland research firm that contracts
with the National Cancer Institute, says natural killer cells have only
lately begun to stir interest in cancer circles. However, the cells are
showing promise not only in leukemia and lymphoma, but also in certain
metastatic solid tumors. "Some people are using activated killer cells
as an immunotherapy without bone marrow transplant," he adds.
Currently, patients
and marrow donors are matched for six immune proteins called HLA (or MHC),
expressed on the surface of certain blood cells. Although five of six
is considered a close match, many patients have only three or fewer of
these proteins in common, and even a single mismatch can lead to devastating
rejection of the transplant. To reduce the chances of rejection, doctors
take pains to knock out a patient's T-cells, which help marshal an immune
reaction against the foreign tissue. Yet, in doing so they make graft
recipients vulnerable to graft-versus-host disease, a potentially deadly
reaction that occurs when immune cells in the transplanted marrow turn
on the already-weakened patient. Taken together, Kinniburgh says, the
two reports suggest T-cell depletion might not be necessary if scientists
pay attention to the natural killer cells of the donor and patient.
In the Italian study,
a team led by Dr. Andrea Velardi of Perugia University first analyzed
cell samples from 92 people with either acute myeloid (AML) or acute lymphoblastic
(ALL) leukemia. All had undergone bone marrow transplants to treat their
disease. The AML patients who received killer cells more antagonistic
to their own tissue, based on molecular receptors they expressed, had
a five-year rate of relapse 60 times lower than those with more agreeable
cells, the researchers say. Velardi's group also showed that giving mice
with severely suppressed immune systems a shot of killer cells wiped out
traces of human leukemia with which they'd been injected. In the second
study, Florida scientists showed that manipulating natural killer cells
in graft recipients may also prove effective at preventing tissue rejection
and treating disease. "What the Italian study is saying is that if we
take NK [natural killer] cells from the donor and let them attack the
host, they'll clean things out. We can do that in the host by just getting
rid of one gene," says lead author William G. Kerr, of the Moffitt Cancer
Center and Research Institute in Tampa.
The gene is called
SHIP, and it produces an important enzyme in the immune response. However,
when mice lack SHIP their natural killer cells lose their will to attack
foreign tissue. Kerr says the finding could lead to drug treatments to
neutralize killer cells by mollifying SHIP. In the meantime, he adds,
the Italian research is farther along clinically. When they start a trial
in patients, he says, "if I had [acute myeloid leukemia] I'd be signing
up." Murphy, who studies
killer cells, says it may also be possible to purify natural killer cells
from a graft donor and use them to supplement the therapy and destroy
residual leukemia. The Italian researchers had success with this approach
in their work in mice, he notes. However, Kinniburgh says, scientists
may "want to creep up on this a little more slowly," especially since
the experiments may involve tinkering with the immune systems of severely
ill patients.
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Electronic
module to classify class of cancer -(Times of India Online-05/02/2002)
In a development
that could help oncologists identify which type of cancer a patient is
suffering from very early in malignancy, scientists have created an electronic
module that predicts the class of the disease by reading genetic information
from the patient's marrow. Presenting their
findings at the first ever international conference on 'Fuzzy Systems'
in India, the two-member team of researchers from the Department of Computer
Science in the Yonsei University of Korea said that the module can predict
the cancer class in the major categories of Acute Myeloid Leukaemia and
Acute Lymphoblastic Leukemia.
Although cancer detection
and class discovery have been seriously investigated over the past three
decades, there has been no general and perfect way to work out this problem,
the computer engineers Jungwon Ryu and Sung-Bae Cho said in their presentation.
This, Ryu said, was because there could be many pathways causing cancer
and the disease itself was manifested in a tremendous number of varieties.
In a work supported by the brain science and engineering research programme
of the Korean ministry of science and technology, the duo worked upon
DNA samples of patients of ALL or AML.
There are 7,129 known
genes in human genome of which only a very few have information related
to cancer. ''We extracted 25 genes and through our cancer predictor classified
the category only with these genes,'' Ryu said. In the experimental stage,
72 patients were scanned to create a DNA microarray sample database. The
DNA microarray consisted of large number of DNA molecules spotted in a
systematic order on a glass slide also called a DNA chip. It is so powerful
that one can investigate the gene information in a short time, because
at least hundreds of genes are put on the DNA microarray to be analysed,
Ryu told international delegates at the four-day conference organised by
the Indian Statistical Institute. These slides were then imaged using
scanner that made fluorescence measurements for each dye. The log ratio
between the two intensities of each dye was used as the gene expression
data.''To find out the
genes that had cancer-related function, we applied seven feature selection
methods already in use for data mining and pattern recognition,'' Ryu
said. The innovative module meets the long-felt need for tools to efficiently
analyse biological genomic information.
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Chemotherapy,
drug combo effective treatment for lymphoma-(Times of India Online-24/01/2002)
Efforts to treat
an increasingly common blood-related cancer known as non-Hodgkins lymphoma
have reached a new plateau, with a regimen combining chemotherapy and
a monoclonal antibody known as rituximab. In a study appearing in the
New England Journal of Medicine, a team of European doctors found that
the remission rate among patients using the combined regimen was significantly
higher than those using chemotherapy alone.
The study of 398 patients
conducted between July 1998 and March 2000, part of a clinical trial by
a European cancer coalition, found that 70 percent of patients treated
with the combined regimen were alive two years later, compared to just
57 percent of patients using only chemotherapy. "The complete remission
rates seen with this new combination are very encouraging and indicate
a real change in the way this disease can be treated from now on," said
study author Bertrand Coiffier, a hematologist affiliated with Gela, which
studies adult lymphomas.
In a separate editorial,
the esteemed medical journal hailed the discovery billed as "an improvement
in overall survival in this increasingly common form of blood cancer"
as a long-awaited advance in the treatment of the fifth most common type
of cancer in the United States. Rituximab, marketed
in more than 70 countries by the Swiss laboratories Roche under the brand
MabThera, blocks CD-20 cell-surface protein found in mature B cells that
become cancerous in patients who suffer from non-Hodgkins lymphoma, which
accounts for about 40 percent of all new cases of lymphoma.
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GM
stem cells hold key to cancer cure -(Times of India Online-11/01/2002)
Fighting cancer by
activating genes selectively into stem cells is possible, researchers
at the Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins have
established. The Science Daily quoted Linzhao Cheng, Ph.D., assistant
professor of oncology at the Johns Hopkins Kimmel Cancer Center and director
of the study, as saying, "Blood stem cells represent an important target
for the treatment of a variety of blood and immune disorders, so our ability
to engineer them to selectively stimulate immune responses opens up new
possibilities for gene therapy." Using a gene known
to produce a fluorescent protein, scientists transferred it into human
adult and cord blood stem cells and injected the cells into immune-compromised
mice. The gene transfer into the stem cells was accomplished via a lentivirus,
genetically engineered to be safe, with coded instructions for the gene
to turn on in a specific type of cell.
Since blood stem
cells differentiate and develop into all blood and immune system cells,
all descendants of the stem cells had the fluorescent protein gene. However,
the gene turns on only when the stem cell developed into one type of immune
cell, called an antigen-presenting cell (APC). APCs play a central role
in controlling immune system responses. Cheng says this is
an important step in providing a new way to achieve targeted gene therap.
Six mice were transplanted with the fluorescent gene made specific for
APCs. After 10 weeks, all produced the fluorescent protein in an average
of 56 percent of the transplanted cells, and exclusively in APCs. Five
control mice were transplanted with the fluorescent gene made universal
for all cells and produced fluorescence in all types of the transplanted
cells.Four additional control
mice without the fluorescent gene showed no fluorescent protein in any
transplanted cells. The researchers will conduct further studies to explore
the possibility of delivering genes that boost the immune system to develop
stronger therapeutic cancer vaccines. Other possible applications of the
technology may be used to suppress the immune system to reduce adult cell
transplant rejection.
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Folic
acid, iron may cut leukaemia risk -(Times of India Online-07/12/2001)
Taking folic acid
and iron supplements during pregnancy may help to reduce the risk of childhood
leukaemia, Australian researchers said. Acute lymphoblastic leukaemia
(ALL) is the most common cancer in children in developed countries, but
scientists at the Cancer Foundation of Western Australia in West Perth
found that folic acid, or folate, and iron were a winning combination
against the disease. In a study to determine risk factors for the cancer,
they found that women who took the supplements while pregnant had a 60
per cent reduced risk of having a child with the disease. Iron pills alone
cut the risk by 25 per cent. Only one mother took folate without iron.
"Our results, though
unexpected, suggest that folate supplementation in pregnancy reduces the
risk of common acute lymphoblastic leukemia in the child," Dr Judith Thompson
said in a study published in the Lancet medical journal. Childhood cancer
affects about one in 600 children and leukemia accounts for about one-third
of all cases. Thanks to improvements in chemotherapy in recent decades
more than 80 percent of children with the cancer beat the disease. Thompson
and her team studied risk factors for all cases of the illness in children
up to 14 years old in Western Australia between 1984 and 1992.
"We recorded an unexpected
significant inverse association between maternal use of iron or folate
supplements in pregnancy and common ALL (acute lymphoblastic leukemia)
in children," said Thompson. Studies have shown
that folic acid supplements can also reduce the risk of neural tube birth
defects such as spina bifida, a leading cause of childhood paralysis.
Folic acid helps the body form red blood cells and aids in the formation
of genetic material within every cell in the body. The U.S. RDA (recommended
daily allowance) for folic acid is 400 micrograms per day. The biggest
sources are vegetables, grain products, nuts and soy. Many ready-to-eat
cereals are fortified with folic acid.
[Back]
New
cancer drug fast-tracked-(Cancer Info-30/10/01)
The Ministry of Health
has fast tracked the registration of a new drug, which is being seen as
a new generation of treatment for cancer. The drug, known as Glivec, is
designed to treat people with a specific form of chronic myeloid leukaemia.
Seven New Zealanders have been involved in an international trial of the
drug, which researchers say has shown spectacular success. The drug company
Novartis says Glivec targets the enzyme that causes cancer cells to grow
and is extremely precise because it leaves the healthy cells intact. Glivec
has been granted approval by the Ministry of Health in roughly half the
normal time for drug assessment. The drug has already been granted similar
approval in the United States, Europe and Australia.
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