Development, verification, and comparison of a risk stratification model to identify potential population benefiting from chemotherapy in non-metastatic male breast cancer.

To establish a prognostic stratification nomogram for non-metastatic male breast cancer to determine which patients can benefit from chemotherapy. A population-based study was conducted using data collected from the surveillance, epidemiology, and end results database. Cox proportional hazards analysis identified significant prognostic factors for survival. A prognostic stratification model was developed using R software. Propensity score matching was implemented to balance characteristics between the chemotherapy cohort and the non-chemotherapy cohort. The multivariate analyses indicated that age, race, grade, surgery, primary tumor, marital status, T stage, and N stage were independent prognostic factors for overall survival in non-metastatic metastatic MBC patients who did not receive chemotherapy (all P < 0.05). The C-index was 0.786 (95% CI 0.662-0.870) in the training cohort and 0.763 (95% CI 0.517-0.852) in the validation cohort. The nomogram effectively discriminated between low-risk, moderate-risk, and high-risk groups concerning OS (P < 0.0001). The current study developed the first prognostic stratification nomogram for non-metastatic MBC and identified that patients in the moderate-risk and high-risk groups are more likely to benefit from chemotherapy.