Clinicopathological characteristics and survival outcomes of male breast cancer according to race: A SEER population-based study

Abstract

To investigate the clinicopathological characteristics and survival outcomes of breast cancer in the male population, 8,607 cases of patients were identified in the Surveillance, Epidemiology, and End Results (SEER) database, including white males (n = 7122), black males (n = 1111), and other males (American Indian/AK Native, Asian/Pacific Islander) (n = 374). Black male breast cancer patients were more likely to be in stages II–IV and have more advanced tumors. The rate of lymph node (LN) involvement at diagnosis was higher in black men than in whites and others. The ER- and PR-positive rates were lower in black men than in whites and others. The distant metastasis rate was higher in blacks than in whites and others. Furthermore, the overall survival (OR) rates and breast cancer-specific survival rates were significantly poorer in blacks than in whites and others (χ² = 29.974, P < 0.001; χ² = 7.285, P = 0.026, respectively). In a multivariate analysis, the results showed that race could also be a prognostic indicator (P < 0.001). Moreover, significant differences were also observed in OS among 1:1:1 matched white, black, and other groups (P < 0.001). Differences in outcomes may be partially explained by differences in tumor grades, LN status, and ER and PR status between the 3 groups. This study might provide insights into a better understanding of male breast cancer.