Breast Conservation Surgery for Breast Cancer in Men

BACKGROUND: Male breast cancer (MBC) is a rare disease, accounting for 1% of all breast cancer diagnosed in the US. The rarity of MBC has limited the development of treatment algorithms specific to men. Therefore, the standard of care has been mastectomy. The safety and feasibility of breast-conserving surgery (BCS) in MBC are unclear. This study assessed whether overall survival (OS) outcomes, local recurrence (LR), and postoperative complications differed between patients with MBC who underwent conservative surgery or mastectomy. STUDY DESIGN: A retrospective search for men aged 18 years or older diagnosed with breast cancer was conducted using the TriNetX network. Cohort 1 included patients who underwent BCS. Cohort 2 included patients who underwent mastectomy. Propensity score matching was conducted using age, BMI, tobacco use, cancer stage and tumor size (T1 to T4), radiation, chemotherapy, hormonal therapy, genetics, and comorbidities. Outcomes of interest were 5-year OS, LR, and postoperative complications. RESULTS: A total of 423 patients underwent BCS, and 1,101 patients underwent mastectomy. After matching, 401 patients per cohort were identified. No difference was observed in 5-year OS with the Kaplan-Meier analysis (Cohort 1: 84% vs Cohort 2: 86%, log-rank test p = 0.412) or with LR (11% vs 13%, p = 0.384). The mastectomy cohort was more likely to have postoperative complications, with a risk of 24% compared with 17% in the BCS cohort (p = 0.011). CONCLUSIONS: No difference was observed in the 5-year OS and LR rate between patients with MBC who undergo BCS or mastectomy. The postoperative complication rate was higher with mastectomies. We conclude that BCS for unicentric MBC is feasible and preferred for T1 and T2 cancers.