247 Background: There are no prospective and few large retrospective studies of male breast cancer (MBC). This study’s aim was to describe our institutional experience with MBC and evaluate the ability of the AJCC staging system to stratify survival. Methods: All MBC cases were identified from our institution’s cancer registry from 1984-2008. Data collected included tumor characteristics, lymph node status, treatment, age, and survival. Results: During the study period 166 MBC cases were identified. Median age at diagnosis was 62 years (range 27-87). Most common presentation was a palpable breast mass (77%). Stage at diagnosis was stage 0 (6%), stage 1 (27%), stage 2 (36%), stage 3 (17%), stage 4 (5%), and unknown (9%). Procedure performed was mastectomy in 148 patients (89%), lumpectomy in 10 patients (6%) and unknown in 8 patients (5%). Median tumor size was 2.0 cm (range 0.2-11.0 cm). Most common histology was invasive ductal carcinoma (91%). Estrogen and progesterone receptor status assessed at diagnosis was positive in 93% and 86% of cases tested respectively. HER2/neu status was positive in 6 of 47 cases tested (13%). Nodal staging was performed by axillary dissection (AD) (70%), sentinel node biopsy (SN) alone (11%), SN and AD (11%) and no axillary staging (8%); 43% were node positive, 47% node negative and 10% unknown. Adjuvant chemotherapy was given to 40 patients (24%), adjuvant hormonal therapy to 42 patients (25%) and adjuvant radiation therapy was used in 33 cases (20%). With a median follow-up of 5.5 years, 86 patients (52%) have died: 44 due to breast cancer, 23 due to causes unrelated to breast cancer, and in 19 the cause of death is unknown. Median overall survival was 9.3 years. Median cancer-specific survival was 16.0 years. For patients initially diagnosed at stage 2, 3, and 4 median cancer-specific survival was 12.9, 7.2, and 0.8 years respectively. Median cancer-specific survival was significantly different for stages 2 vs. 3 (p = 0.03) and 3 vs. 4 (p = 0.0006). Conclusions: MBC most commonly presents as a palpable mass, is hormone responsive, and is most commonly treated with mastectomy. The TNM system appropriately stratifies men with MBC by duration of survival.