Management and outcomes of men diagnosed with primary breast cancer.

BACKGROUND: Fewer than 1% of all breast cancers occur in men. As a result, a distinct lack of data exists regarding the management and outcomes in this cohort. METHODS: Any male patient with pathologically confirmed breast cancer diagnosed between August 2000 and October 2017 at either Massachusetts General Hospital or Brigham and Women's Hospital/Dana-Farber Cancer Institute and their affiliate satellite locations were included. Primary chart review was used to assess clinical and pathologic characteristics. Patient and treatment variables were reported via descriptive statistics. Local-regional failure (LRF), overall survival (OS), breast cancer-specific survival (BCSS), and disease-free survival (DFS) were estimated using the Kaplan-Meier method. RESULTS: 100 patients were included in this study. Median follow-up was 112 months (range 1-220 months). Approximately 1/3 of patients experienced at least a 3-month delay to presentation. 83 patients ultimately underwent mastectomy as definitive surgical treatment. 46 patients received adjuvant radiation therapy, and 37 patients received chemotherapy. Of 82 hormone receptor-positive patients with invasive cancer, 94% (n = 77) received endocrine therapy. Of the fifty-eight patients who underwent genetic testing, 15 (26%) tested positive. The 5-year OS, BCSS, DFS, and LRF rates were 91.5%, 96.2%, 86%, and 4.8%, respectively. Delay to presentation was not associated with worse survival. CONCLUSIONS: Male breast cancer remains a rare diagnosis. Despite this, the majority of patients in this study received standard of care therapy and experienced excellent oncologic outcomes. Penetration for genetic testing improved over time.