LNG-IUS treatment of non-atypical endometrial hyperplasia: Can Pipelle endometrial sampling be an accurate method of follow-up evaluation?

(EH) is a common disease affecting women of all ages [1]. It is clinically important because it can cause abnormal uterine bleeding, and can precede, or occur concurrently, with endometrial carcinoma. There are many progestin therapy regimens available for treatment of EH. The main progestational agents are oral pro-gestogens such as norethisterone acetate, megestrol acetate, and medroxyprogesterone 17-acetate. More recently, the levonorgestrel-releasing intrauterine system (LNG-IUS; Mirena, Bayer Schering Pharma Oy, Turku, Finland) also has been used successfully to treat EH [2,3]. Several observational studies have shown higher regression rates for LNG-IUS than for the oral progestogens [4-6]. However, systematic examination of the literature indicates that the quality of the published data, derived from small sample sizes and short-term follow-up, is relatively poor [5]. In this issue of the Journal of Gynecologic Oncology, Abu Hashim et al. [6] reports a prospective randomized controlled trial (RCT) that compared the efficacy of LNG-IUS with norethisterone acetate (NET) for treatment of non-atypical EH in perimenopausal women. As noted above, there are many reports on the best way to treat this condition, but only observational studies are available to inform clinical practice. Therefore, many gynecologists consider an RCT on the use of oral progestogens versus LNG-IUS in the management of EH to be required [7]. In this sense, the present study carries clinical significance. The authors of the present report found a significantly higher regression rate in the LNG-IUS group than in the NET group at the 3rd-, 6th-and 12th-month follow-up visits (67.8% vs. 47.5%; 79.7% vs. 60.7%; 88.1 vs. 55.7%). These findings match those of a recent meta-analysis of 190 observational studies including 1,001 women. This analysis showed that a significantly higher regression rate was achieved with LNG-IUS than with oral pro-gestins in treatment of non-atypical complex EH (92% vs. 66%). The authors also reported that the LNG-IUS regression time ranged from 3 to 12 months (median, 3 months), a significant proportion of the patients (67.8%) having achieved regression by the 3rd month. This success rate accords with data reported by Lee et al. [8] for a prospective observational study of 12 Korean women diagnosed with EH and treated with LNG-IUS. In that study, complete regression of EH was achieved in all cases (100%, 12/12), most of the patients (66%, 8/12) having attained it within three months. In light of these results, the authors concluded that LNG-IUS is superior to high-dose oral NET therapy …