Surgeon Influence on Variation in Receipt of Contralateral Prophylactic Mastectomy for Women With Breast Cancer.

Importance: Rates of contralateral prophylactic mastectomy (CPM) have markedly increased but we know little about the influence of surgeons on variability of the procedure in the community.
Objective: To quantify the influence of the attending surgeon on rates of CPM and clinician attitudes that explained it.
Design, Setting, and Participants: In this population-based survey study, we identified 7810 women with stages 0 to II breast cancer treated in 2013 to 2015 through the Surveillance, Epidemiology, and End Results registries of Georgia and Los Angeles County. Surveys were sent approximately 2 months after surgery. Surveys were also sent to 488 attending surgeons identified by the patients.
Main Outcomes and Measures: We conducted multilevel analyses to examine the impact of surgeon influence on variations in patient receipt of CPM using information from patient and surgeon surveys merged to Surveillance, Epidemiology, and End Results data.
Results: A total of 5080 women responded to the survey (70% response rate), and 377 surgeons responded (77% response rate). The mean (SD) age of responding women was 61.9 (11) years; 28% had an increased risk of second primary cancer, and 16% received CPM. Half of surgeons (52%) practiced for more than 20 years and 30% treated more than 50 new patients with breast cancer annually. Attending surgeon explained a large amount (20%) of the variation in CPM, controlling for patient factors. The odds of a patient receiving CPM increased almost 3-fold (odds ratio, 2.8; 95% CI, 2.1-3.4) if she saw a surgeon with a practice approach 1 SD above a surgeon with the mean CPM rate (independent of age, diagnosis date, BRCA status, and risk of second primary). One-quarter (25%) of the surgeon influence was explained by attending attitudes about initial recommendations for surgery and responses to patient requests for CPM. The estimated rate of CPM was 34% for surgeons who least favored initial breast conservation and were least reluctant to perform CPM vs 4% for surgeons who most favored initial breast conservation and were most reluctant to perform CPM.
Conclusions and Relevance: In this study, attending surgeons exerted influence on the likelihood of receipt of CPM after a breast cancer diagnosis. Variations in surgeon attitudes about recommendations for surgery and response to patient requests for CPM explain a substantial amount of this influence.