LAUSR

OBJECTIVE We aimed to investigate the effectiveness of continuing medical therapy in patients who did not achieve complete response (CR) despite 9 months of progestin treatment. We also sought to determine the prognostic factors associated with achieving CR among these patients. METHODS We retrospectively analyzed 51 patients with presumed stage IA, grade 1 or 2 endometrioid adenocarcinoma who had persistent disease on biopsy performed at 9-12 months after at least 9 months of progestin-based therapy. Data on clinicopathological factors and oncological and obstetrical outcomes following continuous hormonal treatment were extracted from the patients' medical records and analyzed. Univariate and multivariate analyses for predicting CR were performed. RESULTS Thirty-seven (72.5%) of 51 patients achieved CR after prolonged fertility-sparing treatment. Median time to CR from starting initial progestin was 17.3 months (range, 12.1-91.7 months). On univariate analysis, history of polycystic ovarian syndrome, histologic grade 2, and not achieving partial response (PR) until 12 months were significantly associated with failure to CR (odds ratio [OR], 6.188, 95% confidence interval [CI], 1.405-27.244, p = 0.018; OR, 9.722, 95% CI, 1.614-58.581, p = 0.013; and OR, 21.750, 95% CI, 4.016-117.783, p < 0.001, respectively). Multivariate analysis revealed that not achieving PR until 12 months was an independent prognostic factor predicting failure to CR after prolonged progestin therapy (OR, 21.803, 95% CI, 3.601-132.025, p = 0.001). CONCLUSIONS Continued medical treatment is effective for persistent early endometrial carcinoma after at least 9 months of progestin therapy in young women who want to preserve their fertility.