Male Breast Cancer in Brazil: Epidemiology, Disparities, and Mortality Trends.

PURPOSE: Male breast cancer (mBC) is a rare neoplasm, accounting for < 1% of breast cancers and approximately 1% of male tumors worldwide. Evidence regarding its epidemiology and clinical management in Brazil is limited. This study aimed to analyze epidemiologic and clinical data on mBC in Brazil. MATERIALS AND METHODS: Data were obtained from the Brazilian National Cancer Institute's Hospital Cancer Registries (2000-2022), Population-Based Cancer Registries (2000-2020), and the Mortality Information System (1979-2024). The impact of sociodemographic, clinical, and geographic variables was evaluated by multivariate logistic regression models. Descriptive and temporal trend analyses, using linear regression, were performed. RESULTS: A total of 4,918 cases of mBC were identified. The median age at diagnosis was 60 years, and 75.6% of cases occurred in men 50 years and older. A total of 43% of the patients had ≤8 years of education (43.0%), and advanced clinical stages (II-III) predominated. Only 39.2% received treatment in their city of residence. Incidence remained stable (average age-adjusted rate of 0.71 per 100,000 men-years), whereas mortality increased steadily across all regions (average age-adjusted rate of 0.13 per 100,000 men-years). Delays in starting treatment (> 60 days) have been progressively worsening since 2010. In multivariate analysis, higher staging (stages III and IV) was significantly associated with Black race (compared with White) and low education level. Information regarding staging was significantly better in cases from the southeastern region, compared with other geographic regions of Brazil. CONCLUSION: mBC in Brazil shows rising mortality and frequent diagnosis at advanced stages. Strengthening early detection, expanding access to specialized and genetic services, and reducing regional disparities are essential to improve outcomes for men with breast cancer in Brazil.