Male breast cancer patients between 2010 and 2015 from the Surveillance Epidemiology and End Results database were included. Univariate and multivariate Cox analyses were used to analyse the factors associated with survival. The propensity score matching method was adopted to balance baseline characteristics. Kaplan-Meier curves were used to evaluate the impacts of
adjuvant chemotherapy on survival. The primary endpoint was survival.
RESULTS: We enrolled 514 patients for this study, including 257 patients treated with
chemotherapy and 257 patients without. There was a significant difference in overall survival (OS) but not in
breast cancer-specific survival (BCSS) between the two groups (p < 0.001 for OS and p = 0.128 for BCSS, respectively). Compared with the non-
chemotherapy group, the
chemotherapy group had a higher 4-year OS rate (97.5% versus 95.2%, p < 0.001), while 4-year BCSS was similar (98% versus 98.8%, p = 0.128). The
chemotherapy group had longer OS than the non-
chemotherapy group among HR+, HER2-, tumour size >2 cm, lymph node-positive
male breast cancer patients (p < 0.05). Regardless of tumour size, there were no differences in OS or BCSS between the
chemotherapy and non-
chemotherapy cohorts for lymph node-negative patients (OS: p > 0.05, BCSS: p > 0.05).
Adjuvant chemotherapy showed no significant effects on both OS and BCSS in patients with stage I (OS: p = 0.100, BCSS: p = 0.858) and stage IIA
breast cancer (OS: p > 0.05, BCSS: p > 0.05).
CONCLUSION: