Double Mastectomy and Inherited Breast Cancer
Study found procedure might cut risk of death in half for those with certain genetic mutations
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, however.
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 considered.
"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.