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

Abstract 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. Its validity and utility was demonstrated prospectively across multiple studies. The observational study PONDx characterized the use of Oncotype DX® Breast in routine practice in France and evaluated its decision impact. Of 882 ER-positive BC patients (67% postmenopausal), most (79%) had N0/Nmic node involvement, grade 2 tumors (68%), tumor size 1–5 cm (88%), and ductal histology…