Efficacy of Hormonal Therapies for Decreasing Uterine Volume in Patients with Adenomyosis

STUDY OBJECTIVE: The aim of this study is to evaluate the efficacy of hormonal therapies for inhibiting an increase in uterine volume in patients with adenomyosis. DESIGN: This was retrospective cohort study. SETTING: This study was conducted at Nippon Medical School Musashikosugi Hospital. PATIENTS: A total of 28 women diagnosed with adenomyosis using magnetic resonance imaging. METHODS: After providing informed consent, patients were treated with gonadotropin-releasing hormone agonist (GnRHa group), a low-dose estrogen and progestin combination (LEP group), or dienogest (DNG group) for ≥16 weeks. Uterine volume was assessed using the formula for an ovoid; uterine volumes before and after 16 weeks of treatment were compared. A <5% increase in uterine volume at 16 weeks was considered to reflect inhibition of uterine volume increase and efficacy of the medication. We compared the efficacy rate among the groups. RESULTS: In the GnRHa group, a significant reduction in uterine volume was noted, from 307.4 ± 230.1 to 177.9 ± 142.1 cm(3) (P < 0.001). In the LEP and the DNG groups, there was no significant change (LEP: 226.7 ± 116.6 cm(3) pre-treatment and 230.5 ± 128.6 cm(3) post-treatment, P = 0.85; DNG: 232.6 ± 117.8 cm(3) pre-treatment and 262.1 ± 136.8 cm(3) post-treatment, P = 0.37). The number of responders (efficacy rate) in the GnRHa group, LEP group, and DNG group was 25/26 (96.2%), 7/15 (46.7%), and 6/11 (54.5%), respectively. The efficacy rate of GnRHa therapy was significantly higher than that of LEP or DNG therapy (P < 0.001 and P = 0.005, respectively). CONCLUSION: We conclude that the efficacy of GnRHa in reducing uterine volume should be considered when prescribing hormone therapy for adenomyosis.