Effects of Gonadotropin-Releasing Hormone Analogs on Ovarian Function Against Chemotherapy-Induced Gonadotoxic Effects in Premenopausal Women With Breast Cancer in China A Randomized Clinical Trial

IMPORTANCE Studies of the use of gonadotropin-releasing hormone analogs (GnRHa) to protect ovarian function have shown mixed results. OBJECTIVE To determine whether administering GnRHa during chemotherapy in premenopausal women with breast cancer can reduce ovarian impairment. DESIGN, SETTING, AND PARTICIPANTS This randomized clinical trial, conducted at the Shanghai Jiao Tong University Affiliated Shanghai Sixth People's Hospital and Zhejiang Cancer Hospital in China, was an open-label trial involving premenopausal women aged 18 to 49 years with operable stage I to III breast cancer for which treatment with adjuvant or neoadjuvant cyclophosphamide-containing chemotherapy was planned in 2 parallel groups: treatment with chemotherapy with or without GnRHa. Enrollment occurred from September 2015 to August 2017, and follow-up ended December 2020. The data were analyzed in March 2021. A total of 405 patients were enrolled in the study, among whom 27 patients (6.7%) quit participation voluntarily, 33 (8.1%) did not meet the inclusion criteria and were excluded, and 15 (3.7%) were lost to follow-up. Ultimately 330 patients were included in the primary analysis, including 29 patients with baseline anti-Mullerian hormone levels less than 0.5ng/ mL. INTERVENTIONS Eligible patients were randomly assigned (1:1) to receive chemotherapy with (n = 165) or without (n = 165) GnRHa. In patients randomized to receive GnRHa, 3.6mg of goserelin or 3.75mg of leuprorelin was injected subcutaneously once every 28 days from 1 to 2 weeks before the first cycle of chemotherapy to 4 weeks after the last cycle of chemotherapy. MAIN OUTCOMES AND MEASURES The primary end pointwas the rate of premature ovarian insufficiency (POI) at 12 months after chemotherapy. Premature ovarian insufficiency was defined as anti-Mullerian hormone levels of less than 0.5 ng/mL in this study. The secondary end point was overall survival (OS) and tumor-free survival (TFS). RESULTS A total of 330 eligible patients could be evaluated with complete data, among whom 301 patients (91.2%; GnRHA group: mean [SD] age, 40.6 [6.7] years; control group: mean [SD] age, 40.2 [5.9] years) were eligible for primary end point analysis. At 12 months after the completion of chemotherapy, the POI rate was 10.3%(15 of 146) in the GnRHa group and 44.5%(69 of 155) in the control group (odds ratio, 0.23; 95% CI, 0.14-0.39; P <.001). Anti-Mullerian hormone resumption in the GnRHa group was significantly better than that in the control group (15 of 25 vs 6 of 44; odds ratio, 4.40; 95% CI, 1.96-9.89; P <.001). After a median follow-up of 49 months (range, 25-60 months), the differences in 4-year OS and TFS between the 2 groups were not significant. A post hoc analysis showed that in patients younger than 35 years, the TFS was higher in the GnRHa group than in the control group (93% vs 62%; P =.004; hazard ratio, 0.15; 95% CI, 0.03-0.82; P =.03). CONCLUSIONS AND RELEVANCE This randomized clinical trial found that administering GnRHa in treatment with chemotherapy for premenopausal patients with breast cancer reduces the risk of POI, which promotes the recovery of ovarian function.