Levonorgestrel-releasing intrauterine system for endometrial hyperplasia

Background: In the absence of treatment, endometrial hyperplasia (EH) can progress to endometrial cancer, particularly in the presence of histologic nuclear atypia. The development of EH results from exposure of the endometrium to oestrogen unopposed by progesterone. Oral progestogens have been used as treatment for EH without atypia, and in some cases of EH with atypia in women who wish to preserve fertility or who cannot tolerate surgery. EH without atypia is associated with a low risk of progression to atypia and cancer; EH with atypia is where the cells are structurally abnormal, and has a higher risk of developing cancer. Oral progestogen is not always effective at reversing the hyperplasia, can be associated with side effects, and depends on patient adherence. The levonorgestrel-intrauterine system (LNG-IUS) is an alternative method of administration of progestogen and may have some advantages over non-intrauterine progestogens.

Objectives: To evaluate the effectiveness and safety of the levonorgestrel intrauterine system (LNG-IUS) in women with endometrial hyperplasia (EH) with or without atypia compared to medical treatment with non-intrauterine progestogens, placebo, surgery or no treatment.

Search methods: We searched the following databases: the Cochrane Gynaecology and Fertility Group (CGF) Specialised Register, CENTRAL, MEDLINE, Embase, CINAHL and PsycINFO, and conference proceedings of 10 relevant organisations. We handsearched references in relevant published studies. We also searched ongoing trials in ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry, and other trial registries. We performed the final search in May 2020.

Selection criteria: Randomised controlled trials (RCTs) and cross-over trials of women with a histological diagnosis of endometrial hyperplasia with or without atypia comparing LNG-IUS with non-intrauterine progestogens, placebo, surgery or no treatment.

Data collection and analysis: Two review authors independently performed study selection, risk of bias assessment and data extraction. Our primary outcome measures were regression of EH and adverse effects associated with the LNG-IUS device (such as pelvic inflammatory disease, device expulsion, uterine perforation) when compared to treatment with non-intrauterine progestogens, placebo, surgery or no treatment. Secondary outcomes included hysterectomy, hormone-related adverse effects (such as bleeding/spotting, pelvic pain, breast tenderness, ovarian cysts, weight gain, acne), withdrawal from treatment due to adverse effects, satisfaction with treatment, and cost or resource use. We rated the overall quality of evidence using GRADE methods.

Main results: Thirteen RCTs (1657 women aged 22 to 75 years) met the inclusion criteria. Two studies had insufficient data for meta-analysis, thus the quantitative analysis included 11 RCTs. All trials evaluated treatment duration of six months or less. The evidence ranged from very low to moderate quality: the main limitations were risk of bias (associated with lack of blinding and poor reporting of study methods), inconsistency and imprecision. LNG-IUS versus non-intrauterine progestogens Primary outcomes Regression of endometrial hyperplasia The LNG-IUS probably improves regression of EH compared with non-intrauterine progestogens at short-term follow-up (up to six months) (OR 2.94, 95% CI 2.10 to 4.13; I² = 0%; 10 RCTs, 1108 participants; moderate-quality evidence). This suggests that if regression of EH following treatment with a non-intrauterine progestogen is assumed to be 72%, regression of EH following treatment with LNG-IUS would be between 85% and 92%. Regression of EH may be improved by LNG-IUS compared with non-intrauterine progestogens at long-term follow-up (12 months) (OR 3.80, 95% CI 1.75 to 8.23; 1 RCT, 138 participants; low-quality evidence), Adverse effects associated with LNG-IUS There was insufficient evidence to determine device-related adverse effects; only one study reported on expulsion with insufficient data for analysis. Secondary outcomes The LNG-IUS may be associated with fewer hysterectomies (OR 0.26, 95% CI 0.15 to 0.46; I² = 19%; 4 RCTs, 452 participants; low-quality evidence), fewer withdrawals from treatment due to hormone-related adverse effects (OR 0.41, 95% CI 0.12 to 1.35; I² = 0%; 4 RCTs, 360 participants; low-quality evidence) and improved patient satisfaction with treatment (OR 5.28, 95% CI 2.51 to 11.10; I² = 0%; 2 RCTs, 202 participants; very low-quality evidence) compared to non-intrauterine progestogens. The LNG-IUS may be associated with more bleeding/spotting (OR 2.13, 95% CI 1.33 to 3.43; I² = 78%; 3 RCTs, 428 participants) and less nausea (OR 0.52, 95% CI 0.28 to 0.95; I² = 0%; 3 RCTs, 428 participants) compared to non-intrauterine progestogens. Data from single trials for mood swings and fatigue had a similar direction of effect as for bleeding/spotting, nausea and weight gain. There was insufficient evidence to determine cost or resource use. LNG-IUS versus no treatment Regression of endometrial hyperplasia One study demonstrated that the LNG-IUS is associated with regression of EH without atypia (OR 78.41, 95% CI 22.86 to 268.97; I² = 0%; 1 RCT, 190 participants; moderate-quality evidence) compared with no treatment. This study did not report on any other review outcome.

Authors' conclusions: There is moderate-quality evidence that treatment with LNG-IUS used for three to six months is probably more effective than non-intrauterine progestogens at reversing EH in the short term (up to six months) and long term (up to two years). Adverse effects (device-related and hormone-related) were poorly and incompletely reported across studies. Very low quality to low-quality evidence suggests the LNG-IUS may reduce the risk of hysterectomy, and may be associated with more bleeding/spotting, less nausea, less withdrawal from treatment due to adverse effects, and increased satisfaction with treatment, compared to non-intrauterine progestogens. There was insufficient evidence to reach conclusions regarding device-related adverse effects, or cost or resource use.

Trial registration: ClinicalTrials.gov NCT01074892 NCT03241888 NCT03463252 NCT03992937.