Male breast cancer (MBC) is a rare malignancy with limited evidence-based treatment guidelines, particularly for early-stage disease in younger male patients. Therefore, further research is essential to define optimal therapeutic strategies and improve clinical outcomes. Using SEER data (2000–2020), we conducted a retrospective cohort study of 4551 MBC patients who underwent breast-conserving surgery (BCS) or total mastectomy (TM), stratified by adjuvant radiotherapy (RT). Groups included BCS with RT (n = 285), BCS without RT (n = 291), TM with RT (n = 1048), and TM without RT (n = 2927). Multivariate Cox regression, Kaplan–Meier analysis, subgroup analysis, and propensity score matching (PSM) were used to assess breast cancer-specific survival (BCSS) and overall survival (OS). The maximum follow-up was 251 months, with a median of 71.4 months. The BCS rate was 12.7% (576/4551). Mean patient age was 65.1 ± 12.6 years. In Cox multivariate analysis, with BCS with RT as the reference group, patients receiving BCS without RT, TM with RT, and TM without RT showed significantly higher mortality risks (all P < .05). When TM without RT was used as the reference, BCS with RT remained associated with significantly better BCSS (HR: 0.19; 95% CI 0.08–0.48, P < .001) and OS (HR: 0.48; 95% CI 0.32–0.71, P < .001). Subgroup analyses (Figs. 3 & 4) consistently demonstrated survival advantages for BCS with RT, particularly in stage I–II and younger patients (< 65 years). Additionally, TM with RT improved survival compared to TM without RT in stages II–III (e.g., stage II OS, HR: 1.27, 95% CI 1.05–1.54). After propensity score matching, multimodal analysis shows that stage I-II MBC patients receiving BCS with RT had longer OS than those undergoing TM with or without RT (all P < .05). In patients younger than 65 years or with stage I-II MBC, adjuvant RT following BCS is associated with a survival advantage. For stage II-III patients who underwent TM, adjuvant RT is linked to improved survival outcomes. This study leveraged a large, nationally representative dataset from the SEER database, comprising over 4500 male breast cancer patients, thereby enhancing statistical power and the generalizability of the findings. Stratified and propensity score matching analyses were conducted to explore the interaction between surgical intervention and radiotherapy across various clinical stages and age groups, offering a more nuanced understanding of treatment effects. The study featured a substantial follow-up period, with a median of 71.4 months, enabling the assessment of long-term survival outcomes. The SEER database lacks detailed information on radiotherapy parameters, such as technique, radiation dose, and fractionation schedules, which may limit the precision of treatment effect estimatio. Data on systemic therapies—including endocrine therapy, targeted agents and chemotherapy regimens—were not available, potentially limiting the ability to fully adjust for treatment-related confounding factors. The study design did not account for temporal changes in treatment protocols and clinical practices over the study period, which may influence the interpretation of long-term outcomes.
Wang et al. (Mon,) studied this question.