TUESDAY, Feb. 12 (HealthDay News) -- Women who carry the BRCA1
or BRCA2 mutations that raise the risk for both breast and ovarian
cancer should weigh a new finding that suggests having your ovaries
removed provides greater protection against breast cancer if you
have the BRCA2 mutation.
The preventive strategy has long been contemplated by women in
this high-risk category, and this latest research might help women
trying to decide whether to have the procedure, said study author
Dr. Noah Kauff, a gynecologist, geneticist and assistant attending
physician at Memorial Sloan-Kettering Cancer Center in New York
City.
"There have been studies that looked at BRCA1 and 2 together,
but not 2 alone," Kauff noted. His study is published in the March
issue of the
Journal of Clinical Oncology.
Women with an inherited BRCA1 or BRCA2 mutation have up to an 80
percent chance of developing breast cancer in their lifetime,
according to the American Cancer Society, compared to a lifetime
risk of about 12 percent in the general population.
Carriers of BRCA1 or BRCA2 mutations also have an increased risk
of ovarian cancer, cancer of the fallopian tubes and another
gynecologic cancer called primary peritoneal cancer. The lifetime
risk of ovarian cancer for those with BRCA1 mutation is up to 46
percent, and for those with BRCA2 mutations it is up to 27 percent,
compared to about a 1.5 percent risk in the general population.
Kauff and his colleagues recruited women from 11 centers across
the country in late 2004. For an average of three years, they
followed 509 women aged 30 or older who had a BRCA1 or BRCA2
mutation and had the ovary removal surgery (oophorectomy),
comparing them with 283 women who also had the mutations but did
not elect to have the surgery.
"In the women who elected oophorectomy, if we look at the entire
group, 1 and 2 together, we saw that women who had their ovaries
removed have an 88 percent reduction in the risk of gynecologic
cancer and 47 percent [reduction of risk] in breast cancer," Kauff
said.
But when the women with BRCA2 mutations were looked at
separately, the researchers found the surgery reduced breast cancer
risk by 72 percent -- almost twice as much as the 39 percent
reduced risk in BRCA1 mutation carriers -- a reduction that didn't
reach statistical significance.
The surgery reduced the risk of gynecologic cancer by 85 percent
in women with a BRCA1 mutation, and was suggested in women with
BRCA2 mutations, but the researchers were not able to compute the
level of reduced risk, because few of these women had those
cancers.
When they looked more closely, the researchers found the surgery
had a protective effect on the form of breast cancer known as
estrogen receptor-positive cancer, reducing risk by 78 percent in
both BRCA1 and BRCA2 carriers, but had no effect on ER-negative
breast cancers -- which BRCA1 mutation carriers are more likely to
get.
"I don't think this is going to have a lot of clinical impact
for the average person with a BRCA mutation," said Debbie Saslow,
director of breast and gynecologic cancer for the American Cancer
Society. "For the average person with BRCA mutation, this probably
won't enter into her decision-making." For some, it may confirm
surgery is the right thing to do, she added.
The study also raises some questions, said Dr. Angela R.
Bradbury, director of the Margaret Dyson Family Risk Assessment
Program at Fox Chase Cancer Center in Philadelphia. "This paper
raises a question about whether [the surgery] really reduces the
risk of ovarian cancer in BRCA2," she said. However, she added, the
preventive surgery "still remains the only good option."
More information
To learn more about BRCA1 and BRCA2 mutations, visit the
American Cancer Society.
