Breast cancer is the most common cancer -- diagnosed in about 211,000
U.S. women each year -- and the second-biggest killer cancer, after
lung, among women. That may be why some are willing to do just about
anything to prevent it.
Many women with long histories of breast cancer in their families
have volunteered to donate their bodies to a study raising hope
that a new class of drugs may present women at an increased risk
for breast cancer a safe way to protect themselves.
Studies like this, however, have raised serious ethical concerns
about whether the potential benefits of the drugs outweigh the risks.
The ExCel Trial
The study, referred to as the ExCel trial, is running tests on
Aromasin (exemestane), one of a class of new drugs called aromatase
inhibitors that block formation of estrogen, which can spur the
growth of breast cancer cells.
Such drugs have been found to reduce the relapse rate for breast
cancer at least as effectively as tamoxifen, the only other estrogen-blocking
drug available. (However, tamoxifen has been found to raise the
risk of blood clots, uterine cancer and endometrial cancer, hindering
many women from taking it.)
The ExCel trial will involve:
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About 4,500 postmenopausal women who are considered at high
risk for breast cancer.
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Half the women will take Aromasin while the other will take
a placebo.
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An independent panel of experts will supervise the study and
analyze the data every six months (for five years) for any signs
of unexpected side effects.
The goal? Researchers hope the data will determine whether the
drugs can prevent first cancers, as well as which women are most
likely to be protected by the drugs.
Danger Waits ...
Despite the touted benefits, a number of bioethicists have a problem
with testing new and potentially toxic drugs on healthy women. In
fact, some believe it's difficult to get true informed consent on
studies like these because some women have an overly heightened
fear of breast cancer and likely have a larger expectation of a
benefit than is realistic.
What's more, some findings suggest that aromatase inhibitors may
increase the risk of osteoporosis, making women prone to potentially
serious fractures.
Washington
Post May 22, 2005
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