NeoTAILOR: ABiomarker-directed Approach to Guide Neoadjuvant Therapy for Patients With Stage II/III ER-positive, HER2-negative Breast Cancer

Ki67 scoring determination (standard of care) utilizing the Ki67 MIB-1 assay (clone 30-9) (VENTANA) will be performed at baseline, Week 4 (+/- 14 days - high-risk group only), and at time of surgery in accordance with the International Ki67 in Breast Cancer Working Group guidelines.

Oncotype DX® Recurrence Score (RS) testing - assessing expression of 21 genes including 16 cancer-related genes and 5 reference genes - will be performed as standard of care in a central laboratory (Exact Sciences) on RNA extracted from formalin-fixed paraffin-embedded core-biopsy samples.

This PAM50-based Prosigna breast cancer gene signature assay for intrinsic molecular subtype determination will be performed on formalin-fixed, paraffin-embedded (FFPE) core-biopsy samples.

Standard of care

Standard of care