Objectives The aim of this study was to evaluate the efficacy and safety with gonadotropin-releasing hormone agonist (GnRHa) combined with a levonorgestrel-releasing intrauterine system or an aromatase inhibitor (letrozole) in young women with well-differentiated early endometrial carcinoma (EC) and complex atypical hyperplasia (CAH).

Methods We performed a retrospective analysis including the clinical characteristics of 29 patients younger than 45 years with early well-differentiated endometrioid adenocarcinoma of the uterus (EC) or CAH who were treated at the Department of Obstetrics and Gynecology, Peking Union Medical College Hospital, from January 2012 to April 2016. Eighteen patients were treated with the combination of intramuscular injections of GnRHa every 4 weeks with the levonorgestrel intrauterine hormonal system (Mirena® Bayer Health Care Pharmaceutical Inc, Wayne, NY) was inserted. Eleven patients were treated with the combination of intramuscular injections of GnRHa every 4 weeks with oral letrozole 2.5 mg daily. The patients underwent follow-up with endometrial sampling by hysteroscopy and curettage for endometrial response every 3 months.

Results After a median follow-up of 18.7 months (range, 5.6–54.9 months), 15 women (88.2%) in the EC group and 12 women (100%) in the CAH group had complete response (CR) after GnRHa combination treatment. Among the women who achieved CR, 1 woman (8.3%) with CAH and 1 woman (5.9%) with EC had recurrence after CR, and they finally underwent a hysterectomy. Time to CR was similar in the 2 groups (4.5 ± 1.9 months in the CAH group vs 5.0 ± 2.9 months in the EC group). Ten women (34.5%) had CR after the first 3 months, 8 women (27.6%) had CR after 6 months, and 9 women (31.0%) had CR after 9 months.

Conclusions Both GnRHa with the levonorgestrel-releasing intrauterine system and GnRHa with letrozole are alternative treatments for women with CAH and EC who desire fertility preservation. A larger multicenter trial of the fertility-preserving treatment is warranted.