Korean nationwide analysis of male breast Cancer: Incidence trends, treatment disparities, and survival compared with female patients

Abstract

Background: s: Male breast cancer (MBC) accounts for less than 1 % of all breast cancer cases and is considered a rare disease. However, its incidence is steadily increasing. Despite this trend, comprehensive analyses comparing the clinicopathological characteristics and outcomes between male and female breast cancer (FBC) patients remain limited. Methods: Using Korean National Health Insurance data (2007–2023), we analyzed 368,577 patients (1437 men; 367,140 women). Age-standardized incidence rates (ASR), clinicopathological features (age at diagnosis, Charlson Comorbidity Index), treatment modalities, recurrence rates, and mortality outcomes were compared between MBC and FBC. Multivariate Cox proportional hazards regression was performed to assess the association of sex with recurrence and survival. Results: ASR of MBC doubled (0.59–1.19), while female breast cancer (FBC) increased from 67.6 to 157.3. Male patients were older at diagnosis (64 vs. 51 years, p < 0.001), had higher comorbidity (p < 0.001), and showed worse outcomes. Recurrence was more frequent in men (14.3 % vs. 12.5 %, p = 0.038) as was mortality (31.3 % vs. 11.1 %, p < 0.001). Multivariate analysis confirmed male sex as a significant risk factor for recurrence (p = 0.010). Conclusion: Despite its rarity, MBC incidence is increasing, with distinct clinicopathological features and poorer prognosis compared to FBC. These findings emphasize the need for sex-specific strategies and inclusion of male patients in breast cancer research.