Male breast cancer: A 20-year multicenter experience

Abstract

Aim: Male breast cancer (MBC) is a rare disease and accounts for approximately 1% of breast cancer. Treatment is largely extrapolated from female breast cancer due to lack of data in MBC. However, there are distinct features of MBC that warrant different treatment approach. We aim to better characterize the risk factors, clinicopathologic features, treatment and outcome of MBC patients from six hospitals across Steward Healthcare Network. Materials & methods: A total of 107 men with breast cancer were identified from the respective cancer registry at Steward and 64 patients were included with complete medical records. Their clinical, histopathological and treatment records were retrospectively reviewed. Kaplan-Meier method was used to determine the 5, 10 year overall survival (OS) rate and relapse free survival rate and Cox Regression test was used to assess the association between patient outcome and age at diagnosis, metastasis status at time of diagnosis, tumor size, nodal involvement and use of chemotherapy. Results: Of these 64 patients, median age at diagnosis was 68 years, majority of patients were white, 13 patients had family history of breast or ovarian cancer (20.3%), four patients tested positive for BRCA2 (6.25). Majority of patients presented painless breast lump. A total of 59 patients (92.2%) had invasive ductal carcinoma, and 31 patients (48.4%) had lymph node involvement at time of diagnosis. A total of 62 patients (96.8%) had M0 disease at time of diagnosis. About 97% of patients had estrogen receptor (ER) positive cancer. Most patients underwent mastectomy (87.5%), 35 patients (54.6%) received adjuvant radiation therapy, 19 patients (30%) received adjuvant chemotherapy and 96.7% of patients received adjuvant hormonal therapy. The median follow-up was 71.5 months (range 6-250 months), 5-year survival rate was 86.9% (95% CI: 74.5-93.6%), 5-year relapse free survival rate was 89.9% (95% CI: 77.4-95.7%) and 10-year survival rate was 58.1% (95% CI: 41.0-71.8%). The presence of distant metastasis at the time of initial diagnosis was the only factor associated with shorter OS (hazard ratio: 22.54, p < 0.0001). Conclusion: Majority of MBC patients present with palpable breast mass and the tumors are almost exclusively hormone receptor positive. Majority of patients present without distant metastasis and received surgical therapy; however, only a small subset of patients received breast conserving surgery for T1 tumor. Almost all patients received adjuvant hormonal therapy. OS and relapse free survival in our cohort is similar to historic reports in female breast cancer.