Is repeated high-dose medroxyprogesterone acetate (MPA) therapy permissible for patients with early stage endometrial cancer or atypical endometrial hyperplasia who desire preserving fertility?

Objective: Reports on the repeated administration of medroxyprogesterone acetate (MPA) for intrauterine recurrence after fertility-preserving therapy for atypical endometrial hyperplasia (AEH) and early grade 1 endometrioid carcinoma (G1) are lacking. We aimed to clarify the outcomes of repeated MPA therapy in cases of intrauterine recurrence after fertility-preserving therapy with MPA against AEH/early G1. Methods: Patients with AEH or stage IA well-differentiated endometrioid carcinoma without myometrial invasion who underwent first-line MPA therapy for primary lesions or intrauterine recurrence were divided into initial treatment and repeated treatment groups (162 and 82 patients, respectively). Oral MPA administration (400-600 mg/day) was continued until pathological tumor disappearance. Data regarding clinicopathological factors, adverse events, and outcomes following the initial and repeated hormonal treatments were extracted from medical records and analyzed. Results: Complete response rates in the initial and repeated treatment groups were 98.5% and 96.4%, respectively, among patients with AEH, and were 90.7% and 98.1%, respectively, among patients with G1. In the initial treatment group, 5-year recurrence-free survival (RFS) rates were 53.7% and 33.2% among patients with AEH and G1, respectively. In the repeated treatment group, RFS rates were 14.0% and 11.2% among patients with AEH and G1, respectively. Among patients with AEH, the pregnancy rate tended to be lower in the repeated treatment group than in the initial treatment group (11.1% vs. 29.2%; p=0.107), while no significant group difference was observed among patients with G1 (20.8% vs. 22.7%). Conclusion: Repeated treatment is sufficiently effective for intrauterine recurrence after hormonal therapy for AEH/early G1.