The effect of chemotherapy on survival in patients with nonmetastatic male breast cancer: A population-based observational study

Abstract

Background: Male breast cancer is a rare malignant disease, accounting for <1% of all breast cancers. The treatment of male breast cancer is mainly extrapolated from the enormous literature and clinical experience in women. The objective of the current study was to assess the relationship between adjuvant chemotherapy and survival in a large population-based cohort of patients with early-stage male breast cancer. Methods: Men with invasive stage I to stage III breast cancer were identified in the Surveillance, Epidemiology, and End Results cancer database from 1990 to 2014. The effect of chemotherapy on survival was determined using multivariable Cox regression. Results: Of 2713 male patients enrolled, 1817 (66.9%) did not receive chemotherapy. Age, T classification, N classification, tumor grade, and progesterone receptor (PR) status were found to be strong predictors of chemotherapy administration. Chemotherapy was associated with a significant 26% reduction in all-cause mortality (P