Bilateral mastectomy may not reduce mortality risk

“While it’s been known for some time in the surgical literature that bilateral mastectomy does not impact mortality, this study more clearly confirms that through large sample sizes, length of prospective follow-up, and thoughtful subgroup analysis.”

—Monique Gary, DO

Although rates of contralateral prophylactic mastectomy and bilateral mastectomy are increasing among women with unilateral sporadic breast cancer, a new study reports that despite the procedure diminishing the risk of contralateral breast cancer, the patients experienced mortality rates similar to those of patients treated with lumpectomy or unilateral mastectomy.

The primary goal of the study, appearing in JAMA Oncology (doi:10.1001/jamaoncol.2024.2212), was to determine the 20-year cumulative risk of breast cancer mortality among women with stage 0–III unilateral breast cancer divided by each patient’s initial surgical procedures.

In an editorial accompanying the study, Seema A. Khan, MD, Bluhm Family Professor of Cancer Research at the Feinberg School of Medicine at Northwestern University in Chicago, Illinois, and Masha Kocherginsky, PhD, professor of biostatistics and director of the Quantitative Data Sciences Core at the Robert H. Lurie Comprehensive Cancer Center at Northwestern Medicine, wrote that although contralateral breast cancer is the most frequent second malignant tumor among women who have experienced a diagnosis of primary breast cancer, it is less frequent and less ominous than recurrence of the initial cancer. “Nevertheless,” they wrote, “for many patients with newly diagnosed unilateral breast cancer, it can be a prominent source of worry as they navigate their treatment decisions. This worry is accentuated among young patients and those with early-stage disease.”