304PAssessment of prognostic and therapeutic factors in men with breast cancer

Abstract Background Breast cancer in men is rare, assuming less than 1% of diagnosed breast cancer, requiring extrapolation of results from studies in women. Our objective is to evaluate prognostic and therapeutic factors paying special attention to the effect of hormonal treatment on the evolution of the disease. Methods Observational, retrospective, single-center study of 53 men with breast cancer treated between January 1997 and December 2018. The median follow-up was 66 months (range, 3-282 months). 48 patients had ECOG 0-1 (90.6%), 48 were hormone-receptor-positive (90.5%) and 4 HER2-positive (7.5%). 30 patients had lymph node involvement at diagnosis (56.6%). A total of 45 patients (84.9%) were treated with endocrine therapy (ET) of which 36 received it in adjuvant (67.9%) and 13 in metastatic phase (24.5%). 26 (49.1%) were treated with chemotherapy and 3 with cyclin-dependent kinase inhibitors (5.6%). The association analysis was performed using the Chi-square test and survival analysis with the Log-Rank test in SPSS v25. Results Our cohort had a median age of 68 years (range, 40-88 years). 84% had local or locally advanced stage. The infiltrative histologies were 88.7%. The BRCA gen test was carried out in 43.4%, which was positive in 26.1% of the analyzed patients, with BRCA2 being associated with lower mortality (p = 0.004). The statistic analysis showed greater 5-year overall survival (OS) and cancer-specific survival for ECOG 0-1 (p = 0.010, p = 0.048), absence of vascular invasion (p = 0.033, p = 0.025), Ki67