People
With Blood Cancers Living Longer With New Therapies
September Is
Leukemia, Lymphoma, And Myeloma Awareness Month
For blood cancers
such as leukemia, lymphoma, and myeloma ,
chemotherapy has been the first line of defense until recently.
But new "molecularly
targeted drugs" now are being hailed as precise and powerful
weapons against cancers that are notoriously hard to treat.
This new therapy attacks diseased cells directly and produces
fewer side effects in the process.
"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 (LLS).
"This was the first
place chemotherapy was brought to bear and was successful,"
he says. "We're now at a point from where in 1960 about 4 percent
survived longer than five years and now 85 percent do," Mr.
Kinniburgh says.
To push beyond that
85 percent mark, researchers are pouring their energy into the
development of these molecularly targeted drugs.
To heighten awareness
of these developments, the LLS is observing
September as Leukemia, Lymphoma, and Myeloma Awareness
Month.
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 progression) and
chronic (which develops and progresses 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 (white blood cells found primarily in the bone
marrow) and interferes with the body's immune system.
The cause of these
cancers is uncertain, although they are thought to arise when
a single cell with a genetic flaw starts replicating uncontrollably.
Targeted
Drugs Equate With Success
While chemotherapy
and other conventional treatments are still being used, the
breakthroughs are coming as a result of molecularly targeted
drug therapy.
"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,
of 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,
Dr. 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, Dr. 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.
"We really need new
types of therapies and it may well be that, when chemo (chemotherapy)
is combined with some of the targeted therapies, we could see
a big impact," Dr. Small says.
Dr. 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," Dr. 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," Dr. Small says.
"In AML, there are probably three or four or more altered genes."
Other
New Therapies Take Hold
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," Mr. 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 (chemotherapy)
and/or radiation," Mr. 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," Dr. 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."
Always consult your
physician for more information.
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September 2003
People
With Blood Cancers Living Longer With New Therapies
Targeted
Drugs Equate With Success
Other
New Therapies Take Hold
Substance
in Tomatoes Aids in Heart Disease Prevention
Online
Resources
Substance
in Tomatoes Aids in Heart Disease Prevention
Just one serving a
day of tomato-based foods such as pizza or tomato sauce could
lower your risk for heart disease by as much as 30 percent,
contends a new Harvard University study.
"The results are pretty
enticing," says study author Dr. Howard Sesso, of the Harvard
School of Public Health and Brigham and Women's Hospital in
Boston. "They're encouraging enough for us to do more studies."
The findings appear
in the Journal of Nutrition.
Dr. Sesso and his
colleagues reviewed the diets of approximately 40,000 women
from the ongoing Women's Health Study, which was begun 11 years
ago to follow women who, at the time, were free from cancer
and cardiovascular disease.
The researchers controlled
for factors such as age, family history, smoking status, and
other health indicators.
They found that women
who consumed seven or more servings of tomato-based foods a
week - including tomato juice, tomatoes, tomato sauce, or pizza
- had a nearly 30 percent reduction in risk for cardiovascular
disease compared with women who ate less than one and one-half
servings a week.
The study was sparked
by research that has shown a connection between an increase
in the diet of the antioxidant lycopene and a reduction in risk
for prostate cancer, Dr. Sesso says.
Since tomatoes are
a rich source of lycopene, he and his colleagues were interested
to learn if the same antioxidant qualities, when eaten in tomatoes,
might also lower heart disease risk.
Interestingly, however,
when the researchers tabulated the result, the lycopene intake
itself was not significantly associated with reduced heart disease
risk.
However, when they
looked at food intake, as measured by self-reported servings,
there was a clear cardiovascular benefit for those who consumed
the tomato-based products on a regular basis.
"Our study suggests
preliminary evidence that consuming a number of servings of
tomato-based foods per week may lower the risk of cardiovascular
disease," Dr. Sesso says.
Connie Diekman, director
of university nutrition for Washington University in St. Louis,
finds the study promising, both because the large number of
women surveyed make the results significant and because the
findings concur with other work on the topic.
"The results may still
be inconclusive, but the indication that lycopene/tomatoes may
aid in the prevention of disease continues to evolve," Ms. Diekman
says. "I would encourage people to take these results and add
them to the growing list of studies that point to the benefits
of more fruits, vegetables, and whole grains."
Dr. Sesso points out
that those people who showed the benefit from eating the tomato
foods might just have an overall healthier diet than those who
had fewer servings of tomatoes.
"It could be the diet
itself, one that includes more fruits and vegetables," he says.
"Those people would have a better cardiovascular profile."
"It's hard to be specific,"
Dr. Sesso says of the findings, "but there's a potential that
regular servings of tomatoes can have a dramatic effect on cardiovascular
risk."
Always consult your
physician for more information.
Online Resources
(Our Organization
is not responsible for the content of Internet sites.)
American
Cancer Society
American
Heart Association
Centers
for Disease Control and Prevention (CDC)
Leukemia
& Lymphoma Society
National
Institutes of Health (NIH)
National
Women's Health Information Center
US
Department of Heath and Human Services
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