Objective: To investigate relapse rates after the successful treatment of patients with non-atypical endometrial hyperplasia who were randomised to either a levonorgestrel-impregnated intrauterine system (LNG-IUS; Mirena(®) ) or two regimens of oral medroxyprogesterone acetate (MPA) after primary histological response.
Design: A multicentre randomised trial.
Setting: Ten different outpatient clinics localised in hospitals and seven gynaecological private practices in Norway.
Population: One hundred and fifty-three women aged 30-70 years with low- or medium-risk endometrial hyperplasia met the inclusion criteria, and 153 completed the therapy.
Methods: Patients were randomly assigned to one of the following three treatment arms: LNG-IUS; 10 mg of oral MPA administered for 10 days per cycle for 6 months; or 10 mg of oral MPA administered daily for 6 months. The women were followed for 24 months after ending therapy.
Main outcome measures: Histological relapse of endometrial hyperplasia.
Results: Histological relapse was observed in 55/135 (41%) women who had an initial complete treatment response. The relapse rates were similar in the three therapy groups (P = 0.66). In the multivariable analyses relapse was dependent on menopausal status (P = 0.0005) and estrogen level (P = 0.0007).
Conclusions: The risk of histological relapse of non-atypical endometrial hyperplasia is high within 24 months of ceasing therapy with either the LNG-IUS or oral MPA. Continued endometrial surveillance and prolonging progestogen therapy should be considered.
Tweetable abstract: Relapse of endometrial hyperplasia after successful treatment is independent of therapy regime.
Keywords: Endometrial hyperplasia; levonorgestrel-impregnated intrauterine system; medroxyprogesterone acetate relapse of endometrial hyperplasia; recurrence of endometrial hyperplasia.
© 2015 Royal College of Obstetricians and Gynaecologists.