Benefits of Trimodality Therapy Compared with Systemic Therapy Alone in Male Patients with Stage IV Breast Cancer

Background Male breast cancer (MBC) represents <1% of all breast cancer (BC) diagnoses. Recent publications in female stage IV BC have shown that surgical intervention has a survival benefit. This study aims to determine the impact of surgical intervention in men with stage IV BC and known estrogen (ER) and progesterone receptor (PR) status. Methods The National Cancer Database was used to identify 539 stage IV MBC patients with known ER/PR status from 2004 to 2017. Chi-square tests examined subgroup differences between the treatment modalities received. Overall survival (OS) was assessed using the Kaplan–Meier method. Multivariate Cox proportional hazard models examined factors associated with survival. Results The Kaplan–Meier estimation showed that ER-positive (ER+) and PR-positive (PR+) patients who received surgery, systemic therapy, and radiation (Trimodality) or systemic therapy and surgery (ST+Surg) had improved survival compared with systemic therapy alone (ST) [ER+, p < 0.003; PR+, p < 0.033]. For ER+ patients, the 5-year OS rates by treatment were: Trimodality, 40%; ST+Surg, 27%; and ST, 20%. For PR+ patients, the 5-year OS rates were: Trimodality, 39%; ST+Surg, 24%; and ST, 20%. The Cox proportional hazard model revealed a survival advantage in patients who received Trimodality compared with ST (hazard ratio 0.622; p < 0.002). The timing of systemic therapy in relation to surgery was not found to be significant. Conclusions Trimodality therapy has a survival benefit in stage IV MBC patients with known ER+ status than in male patients who receive systemic therapy alone.