The use of bilateral mastectomy has increased significantly in California, but the results from an observational cohort study show it achieves similar mortality reductions to breast-conserving surgery plus radiation, while unilateral mastectomy is associated with higher mortality.
In an analysis of data from nearly 190,000 patients in the population-based California Cancer Registry, no significant differences were found in all-cause mortality between patients who underwent bilateral mastectomy and those who had breast-conserving surgery with radiation (HR, 1.02 [95%CI, 0.94-1.11]); however, unilateral mastectomy was linked to 35% higher all-cause mortality than was breast-conserving surgery with radiation (HR, 1.35 [95% CI, 1.32-1.39]).
Dr. Allison W. Kurian of Stanford (Calif.)University and colleagues also found the rate of bilateral mastectomy had increased 14.3% each year, from 2% of all patients in 1998 to 12.3% in 2011, with it more commonly used among non-Hispanic white women, those with private insurance, and those who received care at a National Cancer Institute–designated cancer center, according to a paper published Sept. 2 in JAMA [doi:10.1001/jama.2014.10707].
"In a time of increasing concern 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 wrote.
In an accompanying editorial, Dr. Lisa A. Newman of the comprehensive cancer center, University of Michigan, Ann Arbor, said the findings refute patient assumptions that bilateral mastectomy represents their best chance for a cure, and for eliminating the perceived cancer threat to the unaffected breast, and advocated a more calm and considered approach to treatment decision making (JAMA 2014 Sept. 2 [doi:10.1001/jama.2014.11308]).
"Physicians should not permit excessive treatment delays to compromise outcomes, but the initial few weeks surrounding the diagnosis are more effectively utilized by time invested in patient education and procedures that contribute to comprehensive treatment planning as opposed to hastily coordinating impulsive, irreversible surgical plans," Dr. Newman wrote.
The study was supported by the Jan Weimer Junior Faculty Chair in Breast Oncology, the Suzanne Pride Bryan Fund for Breast Cancer Research at Stanford Cancer Institute, and the National Cancer Institute. Two authors reported grants from Genentech for other work, but there were no other conflicts of interest disclosed.