Among women being treated for breast cancer, prophylactic removal of a healthy breast is becoming increasingly common. Among U.S. women with Stage 1 to Stage 3 breast cancer, the rate of such mastectomies jumped by 150% from 1998 to 2003.
But which of them actually improved their health by taking such a dramatic step? A study published online Thursday in the Journal of the National Cancer Institute helps answer that question.
Dr. Isabelle Bedrosian, a surgical oncologist at the University of Texas M.D. Anderson Cancer Center in Houston, and colleagues examined data from the National Cancer Institute’s Surveillance, Epidemiology and End Results registry. They identified 107,106 women who had a mastectomy to treat Stage 1 to Stage 3 breast cancer. Among that group, 8,902 women also had their healthy breast removed.
After crunching the numbers, the researchers discovered one group of patients that actually benefited from the elective surgery – women under 50 with Stage 1 or Stage 2 breast cancer that was estrogen receptor negative. For these women, a prophylactic mastectomy improved their odds of being breast-cancer free after five years by 4.8 percentage points.
“Baseline odds vary,” Bedrosian said in an interview. “Whatever the oncologist tells them is their odds, we’re saying you can improve those odds by 4.8% as a result of having this surgical procedure on top of all the other medical things you do to treat your cancer.”
It may not sound like a big bump, but “in the world of oncology, that is not a small number,” Bedrosian said. “Quite a lot of patients take chemotherapy for a 1% or 2% benefit.”
Still, she acknowledged that a 4.8% survival benefit may not be enough to persuade some patients to remove a healthy breast. Seven percent to 10% of women who have prophylactic mastectomies come to regret the decision, usually because they are unhappy with the cosmetic results, she said.
The study also identified one group of patients that definitely do not benefit from preventive breast removal – breast cancer patients over the age of 60. Those women may find the results of the study reassuring, Bedrosian said.
-- Karen Kaplan
Illustration: New research may help breast cancer patients weigh the pros and cons of a prophylactic mastectomy. Credit: Getty Images