Effect of oral versus intrauterine progestins on weight in women undergoing fertility preserving therapy for complex atypical hyperplasia or endometrial cancer

Objective The objective of this analysis was to evaluate weight changes associated with oral progestin therapies versus the levonorgestrel-containing intrauterine device (LNG-IUD) in women undergoing fertility-preserving therapy for complex atypical hyperplasia (CAH) and endometrial cancer (EMC). Methods All patients diagnosed with CAH or EMC managed with fertility-preserving progestin therapy at two institutions from 1998 to 2012 were identified. Those with serial weight measurements before, during and after therapy were included. Patients were categorized according to the type of progestin therapy administered. The rate of weight change over time of patients treated with oral versus intrauterine progestins was compared using the Mann Whitney U test. Results Sixty patients with EMC (35) or CAH (25) were treated during the study period, with 12 patients receiving multiple regimens. These included megestrol acetate (MA, n = 42), LNG-IUD (n = 22), and other oral progestins (n = 11). The median age at diagnosis was 32 and median pre-progestin body mass index (BMI) was 40.4 kg/m². The median therapy duration was 11.7 months [range: 2.3-118.5]. Median weight change during therapy was greater with MA versus LNG-IUD (+ 2.95 vs. + 0.05 kg, P = 0.03). Patients with a BMI < 35 gained more weight during therapy versus patients with BMI ≥ 35 (+ 2.30 vs. - 0.70 kg/month, P = 0.04); however, in patients with BMI ≥ 35, MA was still associated with more weight gain than LNG-IUD (+ 2.2 vs.-5.40 kg, P = 0.05). Conclusion Oral progestin therapy for conservative treatment of young EMC/CAH survivors is associated with increased weight gain, especially when megestrol acetate is utilized. Utilization of LNG-IUD may result in less weight gain.