Metastatic Male Breast Cancer: A Retrospective Cohort Analysis

Background: Metastasized male breast cancer (MMBC) is a rare disease. Given its low incidence, data regarding tumor biology, current treatment options, and survival rates are scarce. Patients and Methods: A chart review was performed of MMBC patients consecutively registered in regional cancer registries in Germany between 1995 and 2011. Tumor characteristics, treatment, and survival rates were documented and statistically evaluated. Results: 41 men with MMBC represented 25.6% of a total of 160 patients with MBC. 16 (39%) patients showed primary metastases, and 25 (61%) had recurrent metastases. Median survival from occurrence of metastasis was 32 months. Median overall survival (OS) was 68 months. 68.3% (n = 28) of the cohort received systemic therapy favoring endocrine therapy (n = 25, 61.9%). Prolonged metastatic OS (p = 0.02) was observed in patients having had a systemic treatment. Metastatic patients having received endocrine treatment showed significantly prolonged survival rates. Furthermore, patients receiving palliative chemotherapy had a significant survival benefit compared to those in whom chemotherapy was omitted. Conclusion: Our results suggest that systemic treatment in the form of both palliative chemotherapy and endocrine therapy improves outcome of MMBC. Therefore, it seems reasonable that treatment of MMBC should be based on the guidelines for female breast cancer.