OC12.02: Long‐term dienogest administration in women with adenomyosis: effects on ultrasonographic features and symptoms

To evaluate the effects of long-term treatment with dienogest (DNG) on ultrasonographic features of adenomyosis and symptoms. This prospective study included women with adenomyosis diagnosed by transvaginal ultrasonography (TVS) and dysmenorrhea (intensity ≥ 5 on a 10 cm visual analog scale, VAS). Pain symptoms were evaluated using a 10-cm VAS scale. The intensity of bleeding was assessed by using the pictorial blood-loss assessment chart (PBAC) and the measurement of hemoglobin (Hb) levels. The ultrasonographic signs of adenomyosis were evaluated by 2 and 3-dimensional TVS. A scoring system was used, assigning a number from 1 to 4 to each myometrial lesion and junctional zone alteration. A total score was assigned to each patient at each follow-up. 143 patients were included in the study. The median length of follow-up was 4 years (range, 1-6 years). DNG significantly improved pain symptoms (p < 0.001 for dysmenorrhea) and decreased menstrual blood loss (p < 0.001 for Hb levels). At 6-month follow-up, the ultrasonographic score significantly improved compared with baseline (p = 0.007). At 1-year follow-up, DNG significantly decreased uterine volume (p = 0.003), the size of focal adenomyosis foci (p < 0.001), the size (p = 0.021) and number (p = 0.008) of myometrial cysts, the number of linear striations (p = 0.036). The improvement of ultrasonographic signs of adenomyosis persisted during treatment. Excluding menopausal women and patients desiring to conceive, 78.2% of the patients were using DNG at 1-year follow-up, 92.4% at 2-year, 94.8% at 3-year, 98.7% at 4-year, and 100% at 5- and 6-year. The ultrasonographic score worsened after 6 months from the discontinuation of DNG treatment in patients desiring to conceive (p = 0.012) but not in those who became menopausal (p = 0.839). In patients with adenomyosis, DNG improves pain, heavy menstrual bleeding, and ultrasonographic features of adenomyosis. These improvements persist in patients receiving long-term DNG administration.