A retrospective study of metaplastic breast cancer: Treatment and prognosis through chemotherapy followed by radiotherapy.

Metaplastic breast cancer (MBC) is a rare and aggressive form of breast cancer. The effectiveness of chemotherapy followed by radiotherapy (CFRT) for MBC remains controversial. The present study aimed to evaluate the efficacy of CFRT on MBC patients with N0M0. A retrospective study was performed to analyze MBC from the surveillance, epidemiology, and end results database. Breast cancer-specific survival (BCSS) and overall survival (OS) rates were analyzed using the Kaplan-Meier curve. Cox proportional hazard models were used to assess BCSS and OS. CFRT might be a valid therapeutic strategy for MBC with N0M0, especially considered with surgical planning. Of the 4672 MBC patients in the surveillance, epidemiology, and end results registry, our final sample comprised 2260 patients. A total of 602 (26.6%), 292 (12.9%), 638 (28.2%), and 728 (32.2%) patients received non-therapy, only-radiotherapy, only-chemotherapy, and CFRT, respectively. Age, tumor size, tumor grade, surgery, and therapy types were independent indicators for BCSS. The Kaplan-Meier analysis showed that total mastectomy (TM) not breast-conserving surgery (BCS) improved BCSS of MBC receiving CFRT, whereas OS of MBC receving CFRT can not benefit from surgical type. Further exploration illustrated that, for BCSS, only stage T2 and T3 MBC patients underwent BCS and only stage T3 MBC patients underwent TM could benefit from CFRT. However, for OS, all stage MBC patients underwent BCS and only stage T3 MBC patients underwent TM could benefit from CFRT.