Letrozole combined with oral contraceptives versus oral contraceptives alone in the treatment of endometriosis-related pain symptoms: a pilot study

Background: To compare the efficacy and the tolerability of letrozole combined with oral contraceptives versus oral contraceptives alone in treating endometriosis-related pain. Methods: A total of 820 women with endometriosis presented with endometriosis-related pain were enrolled with this study. Patients were randomly treated either with letrozole (2.5 mg/day) combined with oral contraceptives (Desogestrel and Ethinylestradiol Tablets)or oral contraceptives (Desogestrel and Ethinylestradiol Tablets) alone for 6 months. Changes in pain symptoms during treatment and in 1 months after treatment, 6-month follow-up and 12-month follow-up were evaluated. Adverse effects of each treatment protocol were recorded. Results: At completion of treatment, the intensity of chronic pelvic pain continued to decrease during treatment and at 1-month after treatment it was significantly lower than at 6-month follow-up and baseline level both in LE + oral contraceptives group (Mean +/- SD,1.5 +/- 1.4) and in oral contraceptives alone group(Mean +/- SD,2.9 +/- 1.2).The intensity of chronic pelvic pain and deep dyspareunia was significantly decrease at both 1-month after treatment and 6-month follow-up. Conclusions: This treatment for endometriosis is a promising new modality that warrants further investigation.