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.