Ovarian function suppression is not indispensable for early premenopausal breast cancer patients aged over 40 years after chemotherapy

Ovarian function suppression (OFS) is a common treatment for premenopausal HR+ breast cancer (BC) patients, However, its efficacy in patients who tended to undergo ovarian dysfunction after chemotherapy remains uncertain. This study retrospectively collected 1386 premenopausal patients over 40 years old with high-risk early HR + BC receiving chemotherapy at the Sun Yat-Sen University Cancer Center between January 2010 and December 2017. Propensity score matching (PSM) was employed to mitigate selection bias. Serum hormones were utilized to delineate ovarian function recovery (OFR). Kaplan-Meier analysis was conducted to assess disease-free survival (DFS) and overall survival (OS). Among the 1386 high-risk early HR+ breast cancer patients, 258 received OFS treatment while 1128 did not. Following PSM, the 5-year DFS rates for the non-OFS and OFS groups were 82.4% and 80.0%, respectively ( p = 0.62), with corresponding 5-year OS rates of 90.9% and 92.3% ( p = 0.5). In the non-OFS group, 8.86% of patients (100/1128) experienced OFR after chemotherapy. However, the DFS ( p = 0.79) and OS ( p = 0.35) of the OFR group were comparable to those of the permanent chemotherapy-induced menopause group. Within the OFR group, patients with Ovarian Function Recovery Interval Time (OFRIT) ≤ 10 months or Ovarian Function Recovery Duration Time (OFRDT) > 12 months exhibited inferior DFS and OS. Nevertheless, only a small fraction of patients aged over 40 experienced OFRIT ≤ 10 months (3.45%, 39/1128) or OFRDT > 12 months (3.98%, 45/1128) after chemotherapy. For premenopausal HR+ early BC patients aged over 40 years, administration of OFS after chemotherapy may not be imperative.