Multigene assays in early breast cancer: Insights from recent phase 3 studies

Multigene assays (MGAs) guide treatment in early-stage breast cancer (ESBC) enabling selective and effective use of adjuvant chemotherapy (CT). Support for all MGAs had previously been derived from retrospectively-analyzed, prospective studies. Only 2 ESBC MGAs, the 70-gene signature (MammaPrint®) and the 21-gene Recurrence Score (RS) assay (Oncotype DX®), are now supported by entirely prospective randomized phase 3 trials. These studies varied...