Prognostic comparison between male and female breast cancer: a population-based SEER database study.

BACKGROUND

Male breast cancer (MBC) is extremely rare. This research sought to analyze the distinctions in clinical features and prognostic outcomes between male and female breast cancer (FBC), and to further develop the nomogram to estimate overall survival (OS) among MBC patients.

METHODS

This study extracted data from the Surveillance, Epidemiology, and End Results (SEER) database. A total of 165,186 patients with a diagnosis of breast cancer between 2010 and 2015 were included according to predefined inclusion and exclusion criteria, comprising 163,821 FBC cases and 1,365 MBC cases. The chi-square test was employed to assess differences in clinical features between FBC and MBC. Kaplan-Meier analysis and propensity score matching (PSM) were utilized to evaluate differences in breast cancer-specific survival (BCSS) and OS. Cox proportional hazards models were applied to identify independent predictors of OS in MBC patients and these variables were subsequently used to develop a nomogram for predicting 3- and 5-year OS. Its performance and clinical utility were assessed with receiver operating characteristic (ROC) curves, calibration curves and decision curve analysis (DCA).

RESULTS

MBC and FBC showed significant differences in clinical features. Kaplan-Meier analysis revealed that MBC exhibited inferior OS and BCSS compared with FBC. After PSM, MBC still had poorer OS compared with FBC, while BCSS was similar between the two groups. Multivariate Cox regression analysis identified age, marital status, race, grade, chemotherapy, and tumor size as independent predictors of OS in MBC patients. The nomogram was developed to estimate 3- and 5-year OS in MBC patients and showed strong predictive accuracy, as confirmed by ROC curves and calibration curves. Additionally, DCA indicated that the nomogram had favorable clinical utility.

CONCLUSIONS

MBC has a poorer prognosis than FBC. The nomogram for estimating 3- and 5-year OS in MBC patients demonstrates good prognostic performance and may provide practical guidance for individualized clinical management.