PurposeThe best adjuvant treatment in high-risk endometrial cancer remains unclear. Although adjuvant chemotherapy seems to improve overall survival (OS) in locally advanced disease, the role of adding radiotherapy is not certain. We evaluated the outcomes of patients with high-risk endometrial cancer treated with adjuvant chemotherapy followed by radiotherapy.Patients and MethodsWe performed a retrospective analysis of patients with high-risk endometrial cancer (endometrioid histology stages III to IVA or carcinosarcoma, clear cell, or serous histology stages I to IVA) treated with adjuvant carboplatin and paclitaxel, followed by radiotherapy, from 2010 to 2017 at a Brazilian cancer center. The Kaplan-Meier method was used for survival analysis, and prognostic factors were analyzed using the Cox proportional hazards model.ResultsOne hundred forty-six consecutive patients were evaluated. The OS rates were 86.2% at 3 years and 75.4% at 5 years. OS was significantly affected by pelvic lymphadenectomy (P = .001) and positive peritoneal cytology (P < .001). Three- and 5-year disease-free survival (DFS) rates were 78.3% and 69.5%, respectively. The initial site of recurrence was limited to the pelvis in 4.1% of patients, within the abdomen in 1.3%, and extra-abdominal in 11.6%. Patients with grade 1 or 2 endometrioid carcinoma had better prognosis than patients with endometrioid carcinoma grade 3 or nonendometrioid histology (3-year DFS, 93.67% v 68.5%, respectively; P = .0017).ConclusionAdjuvant carboplatin and paclitaxel, followed by radiotherapy, is effective in high-risk endometrial cancer and associated with low rates of pelvic recurrence, which might be explained by the addition of radiotherapy. The high-risk group is heterogeneous, and the benefit of adjuvant treatment in patients with grade 1 or 2 endometrioid carcinoma is less clear.