Oncologic Safety of Gonadotropin-Releasing Hormone Agonist for Ovarian Function Protection During Breast Cancer Chemotherapy

Chemotherapy with a gonadotropin-releasing hormone (GnRH) agonist has been reported to protect against ovarian failure. This retrospective, individual matching study from 5 large institutes in Korea found that disease-free survival and distant metastasis-free survival were better in a GnRH agonist group than in a chemotherapy-alone group. Background: Receipt of a gonadotropin-releasing hormone (GnRH) agonist has been reported to protect against ovarian failure. We sought to determine the oncologic effect of a GnRH agonist with chemotherapy for breast cancer patients. Patients and Methods: Data from 1160 patients aged 20 to 40 years with stage I to III breast cancer who received chemotherapy from 5 hospitals in Korea from 2002 to 2012 were reviewed. A GnRH agonist was provided to 406 patients for ovarian protection during chemotherapy, and 754 patients received chemotherapy without ovarian protection. An individual score-matching strategy was used to create sets matched by age, tumor stage, hormone receptor status, neoadjuvant or adjuvant chemotherapy, and institute. Results: Survival analysis by Cox regression showed that the GnRH agonist group had better distant metastasis-free survival (hazard ratio [HR], 0.59; 95% confidence interval [CI], 0.39-0.89) and disease-free survival (HR, 0.72; 95% CI, 0.52-0.99) than the chemotherapy-alone group. Among patients with hormone receptor-positive breast cancer, the benefit was significant for distant metastasis-free survival (HR, 0.53; 95% CI, 0.29-0.99) and disease-free survival (HR, 0.58; 95% CI, 0.35-0.96). Conclusion: Ovarian protection using a GnRH agonist can be safely considered for premenopausal breast cancer patients for whom chemotherapy is planned.