ERBB2 and primary ovarian failure: We observed that CET was associated with a clinically and statistically significant higher OS compared to ET alone in women >50 years of age with RS ≥26 pT1 and pT2 N0M0 HR+/HER2‐breast cancer, and which suggests that cytotoxic chemotherapy has an impact on reducing mortality that is independent of induction of premature ovarian failure.