Dienogest treatment in women with endometriosis: A retrospective cohort study in Taiwan

OBJECTIVE: To assess the treatment efficacy of dienogest specifically in the Taiwanese population with endometriosis. MATERIALS AND METHODS: Eighty-eight patients diagnosed with endometriosis receiving at least 3 months of dienogest 2 mg once daily, from January 2018 to June 2022, were enrolled. They were divided into two groups: surgery group and non-surgery group. The assessment of pain improvement was based on visual analog scale (VAS) scores (0-100 mm) recorded at 0, 3, 6, and 12 months following the initiation of dienogest. Serum CA-125 value and ovarian endometrioma size were analyzed at 0 and 6 months. RESULTS: A total of 65 patients with endometriosis presented painful symptoms. In the surgery group (N = 28), the initial VAS score was 47.5 mm, which significantly declined to 9.6 mm at 3 months (p < 0.01), then to 7.5 mm, 2.9 mm, and 2.1 mm at 6, 9, and 12 months, respectively. In the non-surgery group (N = 37), the initial VAS score was 65.7 mm, which significantly declined to 13.2 mm at 3 months (p < 0.01) and 4.9 mm at 6 months (p < 0.05), remained low at 0.3 mm at both 9 and 12 months. Endometrioma size (N = 33) exhibited a significant 35% decrease from 38.2 mm to 24.8 mm after 6 months treatment (p < 0.01). Serum CA-125 levels showed significant improvement from 86.5 to 30.2 U/ml (p < 0.01) at 6 months. CONCLUSION: This retrospective cohort study proved that dienogest is effective in reducing endometriosis-associated pain and endometrioma size in Taiwanese population.