A retrospective analysis for early-stage non-endometrioid endometrial cancers

Purpose: This study aimed to investigate treatment outcomes and explore optimal adjuvant treatment options for patients with early-stage uterine serous carcinoma (USC) and clear cell carcinoma (CCC). Materials and Methods:We retrospectively reviewed the records of 63 patients diagnosed with stage I-II (2009 International Federation of Gynecology and Obstetrics [FIGO]) USC or CCC.Survival outcomes were estimated using the Kaplan-Meier method, and comparisons between groups were performed with the log-rank test.Results: Among the 63 patients, 36 (57.1%) had USC and 25 (39.7%) had CCC.According to the revised 2023 FIGO staging system, 23 patients (36.5%) were stage IC, and 40 (63.5%) were stage IIC.Adjuvant treatment included no adjuvant therapy (23.8%), chemotherapy alone (39.7%), radiotherapy alone (28.6%), and combined chemotherapy plus radiotherapy (8.0%).After a median follow-up of 54 months (range, 5 to 227 months), the 5-year progression-free survival (PFS) and overall survival (OS) for the entire cohort were 89.5% and 85.7%, respectively.Patients with CCC had a 5-year PFS of 95.8% and OS of 92.3%, whereas those with USC had a 5-year PFS of 85.1% and OS of 81.4%.Most recurrences (7/63, 11.1%) were distant, occurring predominantly in USC cases (6/7) and 2023 stage IIC (7/7). Conclusion:In this retrospective study, early-stage USC and CCC had very favorable PFS and survival outcomes.Thus, future randomized clinical trial or large cohort study is necessary to determine the optimal adjuvant treatments in these patients.