September 4, 2014 — An increasing number of women are opting for bilateral mastectomies, but those who choose the procedure have no additional survival benefit compared with those who undergo breast-conserving surgery with radiation, according to a study published Tuesday in the Journal of the American Medical Association, NPR's "Shots" reports.
For the study, researchers examined the medical records of California women who had been diagnosed with early-stage breast cancer between 1998 and 2011, totaling 189,734 women.
The study found that women who were treated with breast-conserving surgery had an 83.2% survival rate at 10 years, while women who opted for a double mastectomy had an 81.2% survival rate. By contrast, women who underwent a single mastectomy had a 79.9% survival rate, although researchers said that rate "may be due to other factors" not accounted for in the study, such as being a minority and insurance status (Shute, "Shots," NPR, 9/2).
The study also found that while more than half of the women had breast-conserving treatment, the proportion of women who underwent a double mastectomy increased to 12% between 1998 and 2011. According to the researchers, the trend increased most significantly among women under age 40, from 4% to 33%, over the same time period (AP/Modern Healthcare, 9/2).
The researchers said that most of these younger women had an early or treatable form of the disease, and that many were more likely to be treated at academic medical centers. According to the study, these factors should have bolstered their survival rates.
Scarlett Gomez, lead author and research scientist at the Cancer Prevention Institute of California, said researchers are unsure about why the disparity exists. However, she said any "advantage that comes from lowering your risk of cancer in the [healthy] breast" through a double mastectomy "could be offset by the fact that you're having major surgery" ("Shots," NPR, 9/2).
The study suggested that younger women are opting for a double mastectomy in "an emotional rather than evidence-based decision," such as concerns about whether they have genetic mutations that cause the disease or because they have younger children and want to extend their lifespan (Sifferlin, Time, 9/2).
Editorial Questions Providers' Role
Lisa Newman, a surgery professor and director of the University of Michigan's Breast Care Center, in an accompanying editorial wrote that while the study's results may leave some to wonder if providers are driving the uptick in double mastectomies for financial reasons, a "greater concern ... may be a surgeon's preference based on his/her own experience, regardless of the data."
Newman recommended that patients be given time to process their diagnoses and be educated about various treatment options, risks and benefits before having to make a treatment decision (AP/Modern Healthcare, 9/2).