A controlled clinical trial comparing potent progestins, LNG-IUS and dienogest, for the treatment of women with adenomyosis.

Purpose: To evaluate the efficacy of two progestins, levonorgestrel intrauterine system (LNG-IUS) and dienogest (DNG), for adenomyosis.

Methods: This study enrolled 157 women with adenomyosis, randomized to either LNG-IUS ( = 76) or DNG ( = 81) groups as a controlled clinical trial for 72 months. Participants were classified by three different localizations of adenomyosis: diffuse, focal, and extrinsic. VAS (Visual analog scale) score, days, and amount of uterine bleeding were assessed. Uterine volume or bone mineral density (BMD) were measured by three-dimensional ultrasonography or dual-energy X-ray absorptiometry.

Results: LNG-IUS and DNG comparably reduced pain scores in patients with adenomyosis. With regard to pain control, DNG offered greater efficacy than LNG-IUS in 3 months of treatment. In all types of adenomyosis, the days of bleeding after 12 months with DNG were significantly decreased compared to those with LNG-IUS. The decrease of whole uterine body was transient in any subtypes. A comparable decrease in BMD due to age-related changes in both groups was observed.

Conclusions: LNG-IUS and DNG could be useful for long-term management of adenomyosis. In terms of durations of uterine bleeding, DNG was superior to LNG-IUS for 6 years.