Novel prognostic staging system for patients with de novo metastatic breast cancer

Patients with de novo metastatic breast cancer (dnMBC) have highly variable outcomes. Analysis of dnMBC patients in the National Cancer Database, with validation using the SEER database and an independent cohort from the NCDB, resulted in a novel prognostic staging system on the basis of clinical T category, grade, ER status, PR status, HER2 status, histology, organ system site of metastasis, and number of organ systems involved. Patients were stratified into four distinct subgroups, with three-year OS rates >70% (stage IVA), 50-70% (IVB), 25-<50% (IVC), and <25% (IVD). The authors conclude that these findings could be used to refine the current staging guidelines for patients with dnMBC.