Advanced Physician Search: ER positive, Her2 Negative: Chemo Eligible

This Phase III Trial will determine whether adjuvant chemotherapy (ACT) added to ovarian function suppression (OFS) plus endocrine therapy (ET) is superior to OFS plus ET in improving invasive breast cancer-free survival (IBCFS) among premenopausal, early- stage breast cancer (EBC) patients with estrogen receptor (ER)-positive, HER2-negative tumors and 21-gene recurrence score (RS) between 16-25 (for pN0 patients) and 0-25 (for pN1 patients).

Drug: Ovarian Function Suppression + Aromatase Inhibitor, Drug: Adjuvant Chemotherapy + Ovarian Function Suppression

This study aims to utilize a novel biomarker-driven approach to guide neoadjuvant treatment selection. It is the hypothesis that this will improve clinical response for postmenopausal women with clinical stage II/III ER-positive, HER2-negative breast cancer and identify those who may not require neoadjuvant chemotherapy, with a primary focus on outcomes in Black patients.

Device: VENTANA MIB-1 Ki67 assay, Device: Oncotype DX® Recurrence Score, Device: PAM50-based Prosigna breast cancer gene signature assay, Drug: Combination anthracycline and/or taxane based treatment