Comparison of the effect of oral megestrol acetate with or without levonorgestrel-intrauterine system on fertility-preserving treatment in patients with early-stage endometrial cancer: a prospective, open-label, randomized controlled phase II trial (ClinicalTrials.gov NCT03241914)

OBJECTIVE: To evaluate the effect of levonorgestrel-releasing intrauterine system (LNG-IUS) plus oral megestrol acetate (MA) as fertility-preserving treatment in patients with early-stage endometrial cancer (EEC). METHODS: In this single-center, phase II study with open-label, randomized and controlled design, young patients (18–45 years) diagnosed with primary EEC were screened, who strongly required fertility-preserving treatment. Patients were randomly assigned (1:1) into MA group (160 mg oral daily) or MA (160 mg oral daily) plus LNG-IUS group. Pathologic evaluation on endometrium retrieved by hysteroscopy was performed every 3 months. The primary endpoint was complete response (CR) rate within 16 weeks of treatment. The secondary endpoints were CR rate within 32 weeks of treatment, adverse events, recurrent and pregnancy rate. RESULTS: Between July 2017 and June 2020, 63 patients were enrolled and randomly assigned. Totally 56 patients (26 in MA group; 28 in MA + LNG-IUS group) were included into primary-endpoint analyses. The median follow-up was 31.6 months (range, 3.1–94.0). No significant difference in 16-week CR rate were found between MA and MA + LNG-IUS groups (19.2% vs. 25.0%, p=0.610; odds ratio=1.40; 95% confidence interval=0.38–5.12), while the 32-week CR rates were also similar (57.1% and 61.5%, p=0.743), accordingly. More women in MA + LNG-IUS group experienced vaginal hemorrhage (46.4% vs. 16.1%; p=0.012) compared with MA group. No intergroup difference was found regarding recurrence or pregnancy rate. CONCLUSION: Compared with MA alone, the addition of LNG-IUS may not improve the early CR rate for EEC, and may produce more adverse events instead. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03241914