Therapeutic approach to ovarian cysts in tamoxifen-treated women with breast cancer

Objectives: To present our clinical experience with gonadotropin-releasing hormone agonist (GnRHa) treatment of tamoxifen-treated women who had developed ovarian cysts, and to discuss the diagnostic and therapeutic options in such cases. Methods: The study included six tamoxifen-treated premenopausal women with breast cancer who developed ovarian cysts and were followed up by our outpatient clinic. Tamoxifen was administered orally (20 mg/day). All patients underwent a pelvic examination and vaginal ultrasound using a 5-MHz vaginal probe. Blood samples for serum gonadotropins, estradiol (E(2)) and CA 125 levels were collected at the time of the ovarian cyst detection and every month thereafter. After detection of an ovarian cyst, the women were treated by monthly injections of GnRHa. Results: The patients' mean age was 44 years (range 37-51 years) and all had stage-II or -III breast cancer. The mean duration of tamoxifen administration at the time of ovarian cyst detection was 15 months (range 3-40 months). All six ovarian cysts were found to be simple cysts, measuring more than 30 x 30 mm. Serum E(2) levels of the six patients at the time of ovarian cyst detection were between 939 and 1796 pg/ml and were suppressed to less than 25 pg/ml after GnRHa therapy, After between three and six monthly injections of GnRHa all six ovarian cysts disappeared. On follow-up 6 months later, all patients had a normal pelvic examination. Conclusion: The findings of this preliminary report suggest that GnRHa might be an appropriate treatment for tamoxifen-treated women who develop ovarian cysts. It was demonstrated that the GnRHa caused regression of the ovarian cysts and enabled continuation with the adjuvant tamoxifen treatment.