MONDAY, May 5 (HealthDay News) -- In women who have been
diagnosed with breast cancer, having a known mutation in the BRCA 1
or 2 genes raises the risk of a second cancer, and many of these
women choose to have their second breast removed before that has a
chance to happen.
However, new research suggests that women who
don't have these genetic mutations may still face an
increased risk of a second cancer, especially if they have a family
history of breast cancer or atypical breast cells.
The study involved women with a family history of breast cancer,
although only some had a BRCA mutation. The researchers found that
the risk of cancer in the second breast was about 10 percent,
regardless of whether the woman carried a BRCA mutation or not.
The findings were slated to be presented Sunday at the American
Society of Breast Surgeons' annual meeting, in New York City.
The study suggests that "we may not have identified all of the
genes associated with breast cancer," according to study author Dr.
Shawna Willey, director of the Betty Lou Ourisman Breast Health
Center at the Lombardi Cancer Center at Georgetown University in
Washington D.C.
Many high-risk women may not be advised to have a prophylactic
mastectomy even though it could be potentially lifesaving, she
added.
"Having a prophylactic mastectomy should not be a knee-jerk
reaction to a diagnosis of breast cancer. Women need to consider
this data, as well as other data, and decide whether or not this is
a measure they want to take," advised Willey. She said the findings
may also add to the debate about which breast cancer patients
should have sentinel lymph node biopsies.
"Prevention of secondary breast cancer is becoming increasingly
important," said Dr. Julia Smith, director of the Lynne Cohen
Breast Cancer Preventative Care Program at the New York University
Cancer Institute in New York City. "Because of advances in
treatment, it's possible that many younger women with breast cancer
may live for decades, so we have to focus on what we can do to
prevent a further problem."
And, she said, many of the effective chemotherapy drugs can't be
used a second time because they may be too toxic to healthy cells
if given repeatedly, and cancer cells can become resistant to some
forms of chemotherapy.
"We use our best treatment at the time to try to ensure
long-term survival, but if another breast cancer comes along, we
may be limited," she said.
While women with BRCA mutations are known to have a higher risk
of developing an additional cancer, Willey and her colleagues
wanted to learn if women with a family history but no known BRCA
mutations carried a similar risk.
The analysis included 119 women who were part of the Familial
Cancer Registry. All of the women had been diagnosed with an
initial breast cancer, and had decided to prophylactically remove
the second breast.
When the researchers analyzed the breast tissue from the second
breast, they found cancer about 10 percent of the time, regardless
of whether or not a woman had a BRCA mutation.
If the normal breast cancer cells were atypical -- meaning they
showed precancerous changes -- the risk of breast cancer jumped to
about 50 percent over a lifetime for a woman with a family history
of the disease, according to Willey.
"Not having a BRCA mutation doesn't let you off the hook," Smith
noted.
"There's no question that family history is extremely important.
Even without a BRCA mutation, we counsel women to consider
prophylactic mastectomy if they have a strong family history," she
added.
More information
To learn more about prophylactic mastectomy, visit the
National Cancer Institute.
