LNG-IUS versus oral progestogen treatment for endometrial hyperplasia: a long-term comparative cohort study

What are the regression and hysterectomy rates for women treated with the levonorgestrel-releasing intrauterine system (LNG-IUS) compared with oral progestogens for endometrial hyperplasia (EH)? The LNG-IUS achieves higher regression and lower hysterectomy rates than oral progestogens in the treatment of complex and atypical hyperplasia. The LNG-IUS and oral progestogens are both equally used to treat women with EH. There is uncertainty about whether the LNG-IUS is a better therapy for EH. This comparative cohort study included 344 women recruited from August 1998 until December 2010. Women with complex non-atypical or atypical EH were treated with the LNG-IUS (n 250) or oral progestogens (n 94) in a tertiary referral hospital. We evaluated the proportion of women who regressed or underwent hysterectomy after treatment with the LNG-IUS compared with oral progestogens by logistic regression adjusting for confounding. The time from diagnosis to regression was explored through a survival analysis. The follow-up rate was 95.3. The mean length of follow-up in the two groups was 66.9 SD 35.1 months for the LNG-IUS and 87.2 SD 45.5 months for the oral progestogen group. Regression of hyperplasia was achieved in 94.8 (237/250) of patients with the LNG-IUS compared with 84.0 (79/94) of patients treated with oral progestogens (adjusted odds ratio (OR) 3.04, 95 CI 1.366.79, P 0.001). Hysterectomy rates were lower in the LNG-IUS group during follow-up (22.1, 55/250 versus 37.2, 35/94, adjusted OR 0.48, 95 CI 0.280.81, P 0.004). Endometrial cancer was diagnosed in 8 (33) women who had hysterectomy because of a failure to regress to normal histology during follow-up (n 24). The observational design cannot exclude residual confounding from unmeasured variables. In treating EH, LNG-IUS achieves higher regression rates and lower hysterectomy rates than oral progestogens and should be the first-line therapy. Failure to achieve regression carries a high risk of underlying endometrial cancer and hysterectomy is advised.