Results of PONDx, a prospective multicenter study of the Oncotype DX breast cancer assay: Real-life utilization and decision impact in French clinical practice.

Adjuvant chemotherapy shows clear benefits in HER2-positive and triple-negative breast cancer (BC). Its benefits are less universal in BCs expressing hormone receptors. The 21-gene Oncotype DX Breast Recurrence Score test was designed for HR+, HER2- early-stage BC before decision on adjuvant chemotherapy.