Prospective Clinical Utility Study of the Use of the 21-Gene Assay in Adjuvant Clinical Decision Making in Women With Estrogen Receptor-Positive Early Invasive Breast Cancer: Results From the SWITCH Study.

Background: The 21-gene Oncotype DX Recurrence Score assay is a validated assay to help decide the appropriate treatment for estrogen receptor-positive (ER+), early-stage breast cancer (EBC) in the adjuvant setting. The choice of adjuvant treatments might vary considerably in different countries according to various treatment guidelines. This prospective multicenter study is the first to assess the impact of the Oncotype DX assay in the French clinical setting.