B. K. He1, C. Smith1, C. Chu1, L. Lefbom1, A. Schroen1 1University Of Virginia, Charlottesville, VA, Virgin Islands, U.S.
Introduction:
In 2016, the American Society of Breast Surgeons (ASBrS) published a consensus statement discouraging contralateral prophylactic mastectomies (CPM) in average-risk women with unilateral breast cancer. Despite evidence of no oncologic benefit and related attempts to discourage the practice, CPM remains a common practice among this population.
Methods:
We performed a retrospective cohort study of patients with primary breast cancer who underwent complete mastectomy at a single tertiary center between January 2014 and December 2020. In our analysis, we compared a subset of females who underwent CPM versus those who did not as well as examined trends in CPM before and after the ASBrS statement. Chi-square or Wilcoxon rank sum tests were used.
Results:
Of 605 patients, 161 (27%) underwent CPM during our study period, with the median follow-up time for all patients being 58 months (IQR: 38 to 81). Incidental contralateral breast cancer was identified in only two cases (1.2%). Prior to the publication of the ASBrS statement, the rate of CPM was 23% in 2014-2016 compared with 32% in 2017-2019 following the statement. Rates of CPM decreased to 19% in 2020.
Patients undergoing CPM tended to be younger, more likely to have the BRCA mutation, pursue reconstruction, and elect for nipple or skin-sparing mastectomy (Table 1). No significant difference was found in those undergoing CPM by patient race (p = 0.3). There were no significant differences in rates of recurrence (p = 0.7) or mortality events (p = 0.7) during our study period between women undergoing CPM versus those not.
Conclusion:
In the initial years after the 2016 ASBrS consensus statement on CPM, rates of CPM increased at our institution in contrast to the expected and desired trend. More recent data is needed to clarify rates in the past few years, but surgeons should continue to discourage CPM in average-risk women with unilateral breast cancer. Notably, CPM rates among BRCA patients align appropriately with guidelines catering to this higher-risk population, emphasizing the significance of tailored approaches in different patient groups. Better educational tools and decision aids may impact the trend of increasing CPM rates and enhance a complex shared decision-making process, particularly among the average risk sample.
