TUESDAY, Feb. 11, 2014 (HealthDay News) -- Women diagnosed with
an inherited form of breast cancer might halve their risk of dying
of the disease if they remove both breasts, a new study
"I think we've shown pretty clearly that if you have breast cancer and the BRCA mutation, your best option is to get both breasts removed at the outset," said study author Dr. Steven Narod, a senior scientist with the University of Toronto's Women's College Research Institute, in Canada.
The research, published in the Feb. 11 issue of the journal
BMJ, is the first evidence that shows having a so-called
bilateral mastectomy actually saves the lives of women with early
stage breast cancer and mutations in their BRCA genes, the study
But some doctors not involved with the study said the
conclusions may be a bit premature.
Angelina Jolie brought new attention to gene testing for breast
cancer last May when she announced she carried a mutation in her
BRCA1 gene and was removing both breasts with the hope of avoiding
her mother's fate. Her mother, Marcheline Bertrand, died of cancer
at the age of 56. She had been battling breast and ovarian cancer
for 10 years.
The genes BRCA1 and BRCA2 produce a protein that thwarts tumors.
Certain inherited changes to those genes turn off the protein,
dramatically increasing cancer risk.
On average, about 12 percent of women will get breast cancer
over the course of their lives. But for women who carry BRCA
mutations, the lifetime risk jumps to 60 percent to 70 percent,
according to background information included in the study. They're
also more likely to get cancer at younger ages and to be diagnosed
with more aggressive forms of the disease.
Such mutations are rare, however. They're estimated to account
for about 5 percent to 10 percent of all breast cancers, according
to the study.
For women who only discover that they carry the defective genes
after they've been diagnosed with cancer, it's been unclear whether
removal of the opposite breast actually improves their chances of
The new study traced the cancer histories of nearly 400 women
with stage 1 and stage 2 breast cancer who were diagnosed between
1977 and 2009. All the women came from families known to have
mutations in their BRCA1 or BRCA2 genes. Most of the women had
tested positive for a mutation themselves, and were diagnosed with
cancer in their early 40s. They were followed for an average of 13
When it came time for surgery, 209 women opted to remove only
the breast affected by the cancer, while 181 had both breasts
Over the course of the study, 79 women died of breast cancer --
61 in the group that had only one breast removed and 18 in the
group that had both breasts removed.
After controlling for other factors that might influence
survival -- such as tumor size, age at diagnosis and whether the
cancer had spread to the lymph nodes -- researchers found that
having both breasts removed reduced a woman's chances of dying of
breast cancer by 48 percent during the next 20 years.
The researchers said bilateral mastectomy seemed to do the most
good in the second decade after diagnosis.
"If you have breast cancer and a BRCA mutation -- and if you're going to die of that breast cancer -- you'll likely die in the first 10 years," Narod said. "After the 10 years are up, in most cases, you should consider yourself cured of breast cancer."
"What that means is that women who died between years 10 and 20 didn't die of the first breast cancer, they died of a new [cancer], and you can prevent that," he said.
Narod said his study underscores the importance of genetic
testing, especially for women who are diagnosed at a young age or
who have a strong family history of the disease. For them, a
positive genetic test should help guide treatment decisions.
Not all experts agree that this study is the last word,
Karin Michels, an epidemiologist at Brigham and Women's Hospital
in Boston, said the decision to remove both breasts is a difficult
choice for many women, and one that should be carefully
"It's a very personal decision," said Michels, who wrote an editorial on the study. "I think we cannot just say, 'Here are the statistics: It's a no-brainer.' I think it's not a no-brainer."
For one thing, Michels said, the study was small. It was also an
observational study -- not the preferred double-blind,
placebo-controlled study. There may have been important differences
between the study groups that researchers weren't able to account
for, and those differences may have played a bigger role in
survival than their choice of surgery.
"If we have more and larger studies, they will probably confirm these results, but it's a little premature to say this," Michels said. "It's good evidence, but it's not superb evidence."
For those who aren't ready to part with both breasts, experts
say there are other options.
"We get a lot of women who are diagnosed, and they're young and they get sent to us for fast-turnaround BRCA testing so they can make treatment decisions," said Dr. Mary Daly, chairwoman of cancer genetics at Fox Chase Cancer Center in Philadelphia. "At a time of so much emotion and chaos, I'm not sure they always make the best decision."
"This article sort of shows you that if you're not quite ready to make that decision at the time of the initial diagnosis, you can still go back and remove the other breast later and it probably will still be effective," Daly said.
Only 44 women in the study had both breasts removed at the same
time. Another 137 women chose to have their unaffected breast
removed at a later date. On average, women removed their second
breast about two years after their diagnosis.
Beyond removal of the breasts, Daly said there are other
treatments that can help women with BRCA mutations. Those include
removal of the ovaries, which also decreases the chances of breast
cancer; preventive medications such as tamoxifen; and intensive
monitoring with yearly mammograms and MRIs.
U.S. National Cancer Institutefor more on surgery
to reduce the risk of breast cancer.
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