The authors did find that surgery for the removal of one breast was associated with a higher risk of death than the other options examined in the study.

Randomized trials have demonstrated similar survival for patients with early-stage breast cancer treated with breast-conserving surgery and radiation or with mastectomy. However, previous data show increasing use of mastectomy, and particularly bilateral mastectomy (removal of both breasts) among US patients with breast cancer. Evidence for a survival benefit with this procedure appears limited to rare patient subgroups. “Because bilateral mastectomy is an elective procedure for unilateral breast cancer [in one breast] and may have detrimental effects in terms of complications and associated costs as well as body image and sexual function, a better understanding of its use and outcomes is crucial to improving cancer care,” according to background information in the article.

Allison W. Kurian of the Stanford University School of Medicine, Stanford, Calif., and colleagues used data from the California Cancer Registry from 1998 through 2011 to compare the use of and rate of death after bilateral mastectomy, breast-conserving therapy with radiation, and unilateral mastectomy (removal of one breast).

The analyses included 189,734 patients. The researchers found that the rate of bilateral mastectomy increased from 2.0 percent in 1998 to 12.3 percent in 2011, an annual increase of 14.3 percent. The increase in bilateral mastectomy rate was greatest among women younger than 40 years: the rate increased from 3.6 percent in 1998 to 33.0 percent in 2011, increasing by 17.6 percent annually. Use of unilateral mastectomy declined in all age groups
Bilateral mastectomy was more often used by non-Hispanic white women, those with private insurance, and those who received care at a National Cancer Institute-designated cancer center; in contrast, unilateral mastectomy was more often used by racial/ethnic minorities and those with public/Medicaid insurance.

Compared with breast-conserving surgery with radiation, bilateral mastectomy was not associated with a mortality difference, whereas unilateral mastectomy was associated with higher mortality.

“In a time of increasing concern about over-treatment, the risk-benefit ratio of bilateral mastectomy warrants careful consideration and raises the larger question of how physicians and society should respond to a patient's preference for a morbid, costly intervention of dubious effectiveness,” the authors write.
“These results may inform decision-making about the surgical treatment of breast cancer.”