Introduction/Background High-dose progestins have been the mainstay of conservative treatment of atypical endometrial hyperplasia (AEH) and early EC since Bokhman’s first publication in 1985 until today. One of the treatment options is levonorgestrel-releasing intrauterine device (LNG IUD) but data in regard to its effectiveness is limited.

Methodology Total of 418 patients aged 19–46 years receiving hormonal therapy (HT) (228 (55%) with AEH and 190 (45%) with early EC) were prospectively analyzed from 2009 till 2019. Treatment variants for AEH included LNG IUD (n=169), LNG IUD + gonadotropin-releasing hormone (GnRH) agonist (n=20), high-dose oral medroxyprogesteron acetate (MPA) (n=39). EC treatment options were LNG IUD + GnRH agonist (n=139), LG IUD + GnRH + MPA (n=139), MPA (n=27).

Results HT duration was 6–9 months. Complete response (CR) was observed in 96% of AEH and 88% of EC patients. Post-treatment follow-up for 332 patients lasted for a median of 26 months (from 3 to 149 months). 64% of patients attempted conception, 38% of them via ART. 40% of women in this group gave birth. The rate of recurrence was 23.6% in AEH group and 31.2% in EC group. 65% and 55% of patients respectively were disease-free at 5 years (p=0,021). Possible recurrence risk factors were analyzed: age at diagnosis, body mass index, parity, menstrual history, initial diagnosis, tumor grade, early myometrial invasion, use of ART, birth after HT, LNG IUD maintenance use. Regular menstruations prior to treatment, birth or LNG IUD maintenance use after treatment were associated with better DFS in univariate analysis. Only two latter factors kept significance in multivariate analysis: HR=0,215; 95% CI 0,092–0,506; p<0,001 and HR=0,262; 95% CI 0,119–0,575; p=0,001, respectively.

Conclusion Hormonal therapy of EC is highly effective but carries high risk of recurrence. Birth or maintenance LNG IUD use after treatment were associated with decreased rates of recurrence.

Disclosure Nothing to disclose.