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

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. 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. 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%). Repeated treatment is sufficiently effective for intrauterine recurrence after hormonal therapy for AEH/early G1.