Validation of the newly proposed American Joint Committee on Cancer (AJCC) breast cancer prognostic staging group and proposing a new staging system using the National Cancer Database

The eighth edition of AJCC cancer staging manual incorporated biomarker status into the prognostic staging group (PSG). We used data from National Cancer Database (NCDB) to validate and improve the PSG. All patients had surgery and at least some systemic treatment (endocrine therapy, chemotherapy or HER2 targeted therapy). Information from 420,520 patients was assessed for potential predictors of overall survival (OS), including age at diagnosis...