Objective A number of patients with atypical endometrial hyperplasia and endometrial cancer have not yet given birth when they relapse after achieving complete response with initial fertility-preserving treatment. Often such patients still have a strong desire for fertility preservation; however, there are limited reports in the related literature on the efficacy of fertility-preserving retreatment in patients with relapse. This study intends to evaluate the safety and efficacy of fertility-preserving retreatment in patients with atypical endometrial hyperplasia and endometrial cancer after recurrence following initial fertility-preserving treatment.

Methods Data from 110 patients with atypical endometrial hyperplasia and endometrial cancer who received fertility-preserving treatment in the Department of Obstetrics and Gynecology, Peking University People's Hospital (December 2005 to September 2019) were collected, and a retrospective analysis was performed on the clinical characteristics, histopathology results, and outcomes of 25 patients with recurrence.

Results 25 patients (9 with atypical endometrial hyperplasia and 16 with endometrial cancer) received fertility-preserving retreatment. After a median treatment duration of 5 months (range 3–18), 21 patients (84%, 21/25) achieved complete response and 4 patients (16%, 4/25) had a partial response. The median follow-up time was 19.5 months (range 8–76), and a total of 8 patients (38.1%, 8/21) relapsed. The time from retreatment to complete response for endometrial cancer was significantly longer than that for atypical endometrial hyperplasia (7.5 vs 3 months; p=0.007). Among the 21 patients who achieved complete response, 12 patients had a desire for fertility, among whom 8 patients had a successful pregnancy (66.7%, 8/12) and 6 patients experienced term birth (1 patient with natural pregnancy and 5 patients with assisted reproductive technology). Six patients (50%, 6/12) delivered 6 full-term babies.

Conclusion The response rate is high and obstetrical outcomes are favorable after fertility-preserving retreatment in patients with recurrence of atypical endometrial hyperplasia and endometrial cancer.