BEIJING, June 20 (Xinhuanet) -- Women who have
smaller families and fewer female relatives may underestimate their breast
cancer risk, since the current methods of gauging the risk rely on their family
history, U.S. medical researchers said Tuesday.
A team led by Dr. Jeffrey Weitzel of the
California-based City of Hope cancer hospital has found that some women with
breast cancer had inherited genes that put them at a greater risk for the
disease -- but because of fewer female relatives, they did not have a
family history of the disease to act as an early warning.
The study suggests thousands of young women with
breast cancer -- an estimated 8,000 a year in the U.S. -- aren't offered testing
to identify faulty genes and clarify their medical decisions.
When Weitzel tested over 1,500 women under age 50
with breast cancer, he found about 300 to have mutations in one of the
so-called BRCA genes which increased their risk for developing early and
multiple breast and ovarian cancers.
But fully half of these women had what he called a
"limited" family history for breast cancer -- less than two female relatives on
either side of the family who had lived past age 45.
Most of the risk models used now to determine who
might get genetic testing are based on large families and families where there
are multiple cases. If a woman's family history suggests she might carry
such a gene, she might be offered a test to screen for the mutations.
"In some circumstances, we have to qualify what
family history can tell us," said Weitzel. "It's now medically necessary that
access to care should be broader, and more people should be able to take
advantage of (gene screening), because it may make a big difference in outcome.
Failure to recognize that a woman happens to be a BRCA carrier and do
appropriate prevention procedures could cost a woman her life."
The study also shows that three commonly used
predictive models don't accurately estimate the genetic breast cancer risk for
women without a family history of cancer.
(Agencies)
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