Effect of Luteinizing Hormone–Releasing Hormone Agonist on Ovarian Function After Modern Adjuvant Breast Cancer Chemotherapy: The GBG 37 ZORO Study

Purpose Observational studies suggested that luteinizing hormone–releasing hormone agonists (LHRHa) might prevent premature ovarian failure resulting from adjuvant chemotherapy in premenopausal patients. We aimed to test the efficacy of ovarian function preservation with the LHRHa goserelin in patients with breast cancer. Patients and Methods In a prospective, randomized, open-label, controlled multicenter study, 60 patients younger than age 46 years with hormone-insensitive breast cancer were allocated to receive anthracycline/cyclophosphamide (with or without taxane) –based neoadjuvant chemotherapy with or without goserelin. The first goserelin injection was administered at least 2 weeks before the first chemotherapy cycle, continuing at 3.6 mg subcutaneously every 4 weeks until the end of the last cycle. The primary objective was the reappearance of normal ovarian function, defined as two consecutive menstrual periods within 21 to 35 days at 6 months after end of chemotherapy. Results Fifty-three patients (88.3%) experienced temporary amenorrhea (93.3% with v 83.3% without goserelin). No significant difference was observed regarding the reappearance of menstruation at 6 months after chemotherapy (70.0% with v 56.7% without goserelin; difference of 13.3%; 95% CI, −10.85 to 37.45; P = .284). All but one evaluable patient reported regular menses at 2 years after chemotherapy. Time to restoration of menstruation was 6.8 months (95% CI, 5.2 to 8.4) with goserelin and 6.1 months (95% CI, 5.3 to 6.8) without goserelin (P = .304). Chemotherapy resulted in a decreased ovarian reserve measured by inhibin B and anti-Müllerian hormone during follow-up, supporting the other findings. Conclusion Premenopausal patients with breast cancer receiving goserelin simultaneously with modern neoadjuvant chemotherapy did not experience statistically significantly less amenorrhea 6 months after end of chemotherapy compared with those receiving chemotherapy alone.