A post hoc analysis of the RxPONDER trial found that premenopausal patients with HR+HER2- BC and higher anti-Müllerian hormone (AMH) levels (≥10 pg/mL), indicating normal ovarian reserve, experienced benefit with the addition of chemotherapy to ET (HR = 0.48; 95% CI = 0.33 to 0.69) compared with patients with lower AMH levels (<10 pg/mL (HR = 1.21; 95% CI = 0.60 to 2.43), indicating that the amenorrhea as a result from chemotherapy may provide the observed clinical benefit.26 This evidence concerns the gene ERBB2 and amenorrhea.