Gonadotropin-Releasing Hormone Agonists for Ovarian Function Preservation in Premenopausal Women Undergoing Chemotherapy for Early-Stage Breast Cancer: A Systematic Review and Meta-analysis.

IMPORTANCE: Chemotherapy may result in a detrimental effect on ovarian function and fertility in premenopausal women undergoing treatment for early-stage breast cancer (EBC). To minimize risk of harm to ovarian function and fertility for patients in this setting, careful considerations should be made. Gonadotropin-releasing hormone agonists (GnRHa) have been suggested as an alternative to prevent the loss of ovarian function due to exposure to cytotoxic agents, but GnRHa use for ovarian protection in EBC patients is not fully resolved.

OBJECTIVE: To determine the effectiveness of GnRHa administered concurrently with chemotherapy for ovarian function preservation.

DATA SOURCES: PubMed, SCOPUS, and Cochrane databases were searched for studies published between January 1975 and March 2015. The abstracts of the American Society of Clinical Oncology Annual Meeting between 1995 and 2014 and the San Antonio Breast Cancer Symposium between 2009 and 2014 were searched as well.

STUDY SELECTION: Prospective, randomized, clinical trials addressing the role of ovarian suppression with GnRHa in preventing early ovarian dysfunction in premenopausal women undergoing treatment for EBC were selected.

DATA EXTRACTION AND SYNTHESIS: Data extraction was performed independently by 2 authors. The methodology and the risk of bias were assessment based on the description of randomization method, withdrawals, and blinding process.

MAIN OUTCOMES AND MEASURES: Rate of resumption of regular menses after a minimal follow-up period of 6 months following chemotherapy was used as a surrogate to assess the incidence of ovarian dysfunction. Additional secondary outcomes included hormone levels and number of pregnancies. Risk ratio estimates were calculated based on the number of evaluable patients. Analyses were conducted using a random effect model.

RESULTS: Seven studies were included in this analysis, totaling 1047 randomized patients and 856 evaluable patients. The use of GnRHa was associated with a higher rate of recovery of regular menses after 6 months (odds ratio [OR], 2.41; 95% CI, 1.40-4.15; P = .002) and at least 12 months (OR, 1.85; 95% CI, 1.33-2.59; P < .001) following the last chemotherapy cycle. The use of GnRHa was also associated with a higher number of pregnancies (OR, 1.85; 95% CI, 1.02-3.36; P = .04), although this outcome was not uniformly reported and fertility or rate of pregnancy was not the primary outcome in any of the trials.

CONCLUSIONS AND RELEVANCE: Gonadotropin-releasing hormone agonists given with chemotherapy was associated with increased rates of recovery of regular menses in this meta-analysis. Evidence was insufficient to assess outcomes related to GnRHa and ovarian function and fertility and needs further investigation.