Ovarian function preservation with GnRH agonist in young breast cancer patients: does it impede the effect of adjuvant chemotherapy?

Background: Concurrent endocrine therapy with chemotherapy had a concern of potential antagonism. However, gonadotropin-releasing hormone (GnRH) agonist has been used concurrently with chemotherapy to prevent premature ovarian failure for young breast cancer patients. The aim of this study was to determine the impact of concurrent use of GnRH agonists on relapse-free and overall survival, and to establish the oncologic safety of ovarian protection with GnRH agonists.

Methods: Premenopausal women aged between 20 and 40 years who received adjuvant chemotherapy for breast cancer from January 2002 to April 2012 were classified into two groups; One treated with GnRH agonists for ovarian protection during chemotherapy, and the other without ovarian protection. A propensity score matching strategy was used to create matched sets of two groups with age, pathologic stage, hormone receptor, and Her2 status.

Results: A total of 101 patients treated with concurrent GnRH agonist during chemotherapy were compared with 335 propensity score matched patients. Among them, 81.2% were younger than 35 years and 58.4% were hormone responsive. Survival analysis using stratified Cox regression showed that women treated with concurrent GnRH agonists had better recurrence-free survival (adjusted Hazard ratio 0.21, p = 0.009; unadjusted Hazard ratio 0.33, p = 0.034).

Conclusions: Ovarian protection using GnRH agonists can be safely considered for young women with breast cancer in terms of oncologic outcomes. Further studies are needed to assess the long-term outcomes of concurrent GnRH agonist use with chemotherapy.