Bilateral Mastectomy Rates on the Rise, Particularly Among Younger Women

A new study has shown that while there was an increase in the percentage of women diagnosed with early-stage breast cancer undergoing a double mastectomy, the increase was not associated with a lower risk of death compared to breast-conserving surgery plus radiation. However, the study did show that unilateral mastectomy was associated with a higher risk of death compared to double mastectomy and breast-conserving surgery.

The study, published September 3 in the Journal of the American Medical Association, examined data from 189,734 women who were diagnosed with stages 0-III unilateral breast cancer in California from 1998 through 2011 to compare the use of, and the rate of death after, bilateral mastectomy, breast-conserving therapy with radiation, and unilateral mastectomy.

The researchers found that the rate of bilateral mastectomy increased from 2% in 1998 to 12.3% in 2011, an annual increase of 14.3%. The increase in the bilateral mastectomy rate was greatest among women younger than 40 years: the rate increased from 3.6% in 1998 to 33% in 2011, increasing by 17.6% annually.

The study showed that 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, while 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 (HR = 1.02 [95% CI, 0.94-1.11]; 10-year mortality, 18.8% [95%CI, 18.6%-19.0%]), whereas unilateral mastectomy was associated with higher mortality (HR = 1.35 [95% CI, 1.32-1.39]; 10-year mortality, 20.1% [95% CI, 19.9%-20.4%]).

“In a time of increasing concern about overtreatment, 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 wrote. “These results may inform decision-making about the surgical treatment of breast cancer.”