Adjuvant radiation therapy in early-stage endometrial cancer with abnormal beta-catenin expression is associated with improved local control

Objectives. Emerging data suggests that abnormal (nuclear) 13-catenin expression in some settings is associ-ated with poorer outcomes. Our study aimed to verify the significance of abnormal 13-catenin expression in early-stage endometrial cancer patients and determine if adjuvant radiation therapy (RT) improves local control. Methods. We identified 213 patients with FIGO 2018 stage I-II endometrioid endometrial cancer who under-went surgery from 2009 to 2021 with 13-catenin expression assessed. Vaginal, regional, and distant recurrences were analyzed using competing risk methods, and overall survival was analyzed using Kaplan-Meier.Results. Median follow up was 53.2 months; 6.9% experienced vaginal, 8.2% regional, and 7.4% distant recur-rence. For the entire cohort, abnormal 13-catenin expression was significantly associated with vaginal recurrence and remained significant on multivariate analysis (p = 0.03). There were 114 patients in the no specific molec-ular profile (NSMP) subgroup, and abnormal 13-catenin expression was present in 46.5%. In the NSMP subgroup, abnormal 13-catenin expression was associated with increased rates of vaginal recurrence (p = 0.06). Abnormal 13-catenin expression in the NSMP subgroup was significant on multivariate analysis for vaginal recurrence (p = 0.04). RT significantly decreased vaginal recurrences in the entire cohort in patients with abnormal 13-catenin ex-pression (0%) versus wild type expression (17.5%; p = 0.03). In the NSMP subgroup 0% of patients who received RT versus 20.9% of patients who did not receive RT experienced a vaginal recurrence (p = 0.03).Conclusion. Use of adjuvant RT for stage I-II NSMP endometrial cancer with abnormal 13-catenin expression improved local control. RT should be considered in these patients to decrease risk of vaginal recurrences.(c) 2023 Elsevier Inc. All rights reserved.