GnRH agonist therapy as ovarian protectants in female patients undergoing chemotherapy: a review of the clinical data

BACKGROUND: Cancer survival rates in young women are improving due to progress in treatment. This includes aggressive chemotherapy, a treatment that often poses a threat to fertility. GnRH agonists were proposed as ovarian protectors during gonadotoxic therapies. This study was undertaken in order to determine the clinical evidence concerning this issue. METHODS: The medical literature was searched for studies that reported on ovarian function after the administration of GnRH agonists concomitant with chemotherapy. Twelve studies met the predetermined selection criteria. RESULTS: Data on ovarian function were obtained for 579 women who received chemotherapy. Among 345 women who received GnRH agonist co-treatment, ovarian function was preserved in 91% and 9% had premature ovarian failure. In 234 women who did not receive GnRH agonist co-treatment, ovarian function was preserved in 41% and failed in 59%. Only two of the studies were randomized. The control and the GnRH agonist groups differed in several important characteristics: the follow-up times were not equal, different treatment protocols were utilized and end-points were poorly defined and inconsistent between the studies. CONCLUSIONS: The effectiveness of GnRH agonists as fertility-preserving agents is debatable. A thorough literature search has found insufficient evidence to show that GnRH agonist co-treatment is effective in protecting the ovary from the damage of chemotherapy. A large randomized controlled trial with adequate follow-up is needed.