ROR1 in Endometrial Carcinoma: Correlation With Clinicopathological Features, Survival, and Prognosis

ABSTRACT Endometrial carcinoma (EC) is a common gynecological malignancy whose incidence has been increasing globally. Receptor tyrosine kinase‐like orphan receptor 1 (ROR1) has been implicated in several cancers, but its clinicopathological and prognostic significance in EC remains unclear. A total of 66 EC patients who underwent surgical treatment between September 2017 and September 2018 were included. Paired tumor and adjacent normal tissues (> 3 cm from the tumor margin) were analyzed by immunohistochemistry using a validated anti‐ROR1 antibody. ROR1 expression was semi‐quantitatively scored based on staining intensity and the percentage of positive cells, with scores ≥ 6 indicating high expression. Associations between ROR1 expression and clinicopathological features were evaluated using χ 2 tests and logistic regression. Univariate and multivariate logistic regression models identified independent predictors of high ROR1 expression, and model fit was assessed using the Hosmer–Lemeshow test and ROC analysis. Kaplan–Meier and Cox proportional hazards models were used to assess the prognostic impact of ROR1 expression on overall survival (OS), with subgroup analyses stratified by clinical stage and histological type. ROR1 was highly expressed in 65.15% (43/66) of EC tissues compared with 22.73% (15/66) of adjacent normal tissues ( p < 0.05). The mean number of ROR1‐positive cells was significantly greater in high‐expression tumors (86.15 ± 9.79) than in normal endometrial tissue (3.13 ± 1.25) or low‐expression tumors (6.08 ± 3.37) ( p < 0.05). High ROR1 expression was significantly associated with advanced clinical stage (III–IV), Type II histology, lymph node metastasis, and poor prognosis (all p < 0.05). Multivariate logistic regression confirmed that ROR1 overexpression was independently associated with advanced stage (OR = 11.59, p = 0.004), Type II histology (OR = 4.68, p = 0.031), and poor prognosis (OR = 5.68, p = 0.036). Kaplan–Meier analysis demonstrated that patients with high ROR1 expression had a shorter median OS (46 vs. 59 months, p < 0.001). Subgroup analyses revealed that the prognostic value of ROR1 was most evident in Stage I–II and Type I EC, where high expression remained an independent predictor of poor survival after multivariate adjustment (HR = 4.07, 95% CI: 1.71–9.66, p = 0.0015). ROR1 is markedly overexpressed in endometrial carcinoma and independently associated with advanced stage, Type II histology, and adverse prognosis. High ROR1 expression predicts shorter overall survival, particularly in early‐stage and Type I EC, supporting its potential as a prognostic biomarker. Given the retrospective single‐center design, limited sample size, and absence of molecular validation, further multicenter and mechanistic studies are warranted to confirm these findings.