BRCA Breast Cancers Aren't More Deadly
Study Shows Mutations in BRCA Genes Don't Influence Survival Rates
Researchers compared cancer-specific survival outcomes among Israeli women
with BRCA1 or BRCA2 gene mutations to women without the genes in the new study,
published in the July 12 issue of The New England Journal of
They found no difference in survival among the two groups, challenging the
common belief that breast cancers occurring among BRCA carriers are more deadly
than cancers in noncarriers.
"We know that women with BRCA1 and BRCA2 mutations tend to show up with
bad prognostic factors -- characteristics that suggest they are at very high
risk," researcher Gad Rennert, MD, PhD, tells WebMD. "But our results
suggest the outcomes among these women are often much better than would be
BRCA Mutations Uncommon
Inherited gene mutations account for just 5% to 10% of all breast cancers
diagnosed in the U.S. BRCA1 and BRCA2 mutations are the most common ones linked
to hereditary breast cancer and ovarian cancer, but the lifetime risk of
developing breast cancer is between three times and seven times higher for
carriers than noncarriers, according to the National Cancer Institute.
People of Ashkenazi Jewish descent are five times more likely to have
inherited BRCA mutations than the general population.
Because Israel has a very high concentration of Ashkenazi Jews as well as a
national breast cancer registry, Rennert and colleagues from the nation's
National Cancer Control Center were able to compare long-term breast cancer
outcomes among a large group of BRCA carriers and noncarriers.
The researchers first tested DNA from stored tumor specimens obtained from
breast cancer patients treated in Israel in 1987 and 1988 to determine the
incidence of BRCA mutations.
They then reviewed the medical records of the women from whom the specimens
were collected for a minimum of 10 years after diagnosis.
A BRCA1 or BRCA2 mutation was identified in 10% of the samples tested from
women who were of Ashkenazi Jewish descent, and the 10-year follow up revealed
that women who carried a BRCA mutation and women who were not carriers had
similar survival rates.
Rennert says the findings should serve to reassure women who are at high
risk for developing breast cancer because they carry a BRCA mutation.
He noted that classic predictors of poor outcome, such as tumor size at
diagnosis and lymph node status, did not appear to impact survival among the
women in the study.
"Most [BRCA carriers] who develop breast cancer will survive their
disease," he says. "That is an important message to get out to women
and their doctors."
BRCA Mutations and Research
Patricia Hartge, ScD, who wrote an editorial accompanying the study, calls
the findings "generally reassuring" for women who carry BRCA
The National Cancer Institute official says that as more genes linked to
individual cancers are identified, more researchers will examine the role of
these genes in cancer outcomes.
She writes that it may soon become routine to re-evaluate clinical trial
results with genetics in mind.
"There is an argument that 2007 has been the year of the genome in
cancer," she tells WebMD. "Very soon I think we well see an explosion
of studies examining the influence of genes in treatment outcomes."