Polycystic Ovarian Morphology may be a Positive Prognostic Factor in Patients with Endometrial Cancer who Achieved Complete Remission after Fertility-Sparing Therapy with Progestin

Background: The most studied fertility-sparing therapy for endometrial cancer (EC) is oral progestin therapy. However, complete remission (CR) rate after progestin therapy is not enough ranging from 60 to 80 %, with high recurrence rate. Clinical features that predict treatment efficacy and recurrence after progestin therapy have not yet been revealed in detail. The aim of this study was to investigate prognostic factors in patients with EC who achieved CR after medroxyprogesterone acetate (MPA) therapy. Methods: We retrospectively reviewed 35 EC patients treated with MPA at our institution between 2000 and 2016. Following confirmation of endometrioid adenocarcinoma G1, patients orally took 600 mg MPA daily for 26 weeks. Patients with CR periodically took oral contraceptives. The association of recurrence-free survival (RFS) with several clinical features including age, body mass index (BMI), and polycystic ovarian morphology (PCOM) was analyzed. Results: Of 35 patients, 25 (71%) achieved CR, whereas 10 (29%) underwent hysterectomy due to failure of MPA therapy. Eleven (44%) of 25 patients with CR successfully gave birth after MPA therapy, whereas 8 (32%) developed recurrence. On univariate analysis, PCOM was significantly associated with better recurrence-free survival (RFS) (P=0.009), and BMI ≥25 kg/m2 exhibited a nonsignificant trend for longer RFS (P=0.0674). Although multivariate analysis failed to detect any valid hazard ratio (HR), absence of PCOM and non-obesity were both independent risk factors for recurrence (P=0.00293 and P=0.0201, respectively). Notably, none of 10 cases with PCOM experienced recurrence under maintenance with oral contraceptives. Conclusion: PCOM might be a good prognostic factor in those achieving CR after MPA therapy for EC.