Abstract: Objective：To investigate the expressions of folate receptor alpha (FRα) and carbohydrate antigen 125 (CA125) in the endometrial cancer (EC) tissues, and to analyze their possible roles in the occurrence，progression and prognosis of EC. Methods: The 62 patients with EC who were admitted to our hospital from July 2015 to December 2018 were selected as the EC group. 42 patients with atypical hyperplasia of the endometrium were selected as the atypical hyperplasia group and 42 patients with normal endometrium as the normal group. The expressions of FRα and CA125 in the endometrial tissues were tested by immunohistochemistry. The tumor size, differentiation degree, clinical stage, lymph node metastasis and the myometrial invasion depth were compared in those patients with EC. The relationship between FRα and CA125 expression, and the one-year recurrence rate of EC patients, was analyzed. Results: The positive rates of FRα and CA125 expression in the endometrial tissues of the EC group were higher than those in the atypical hyperplasia group and the normal control group (all P＜0.05). There were no significant differences in the expressions of FRα and CA125 between EC patients with different tumor size and lymph node metastasis (P＞0.05). The expressions of FRα and CA125 in the EC patients with the degree of tumor differentiation from G2 to G3, clinical stage Ⅲ to Ⅳ, and the myometrial invasion depth ≥ 1/2 were higher than those in those EC patients with tumor differentiation G1, clinical stage Ⅰto Ⅱ, and the myometrial invasion depth ＜1/2 (P＜0.05). The Spearman correlation analysis confirmed that there was a positive correlation between FRα and CA125 expression in the endometrial tissues of the EC group（rs=0.328，P=0.009）. The one-year recurrence rate in the patients with higher expressions of FRα and CA125 was higher than that in other patients with lower expressions, but the difference was not significant (P＞0.05). Conclusions: The expressions of both FRα and CA125 in the EC tissues are increased. Both FRα and CA125 can be used as the possible indicators for the pathological diagnosis and malignant degree evaluation of EC.

Key words: Endometrial neoplasms, Carcinoma, Folate receptor alpha, Folic acid, CA-125 antigen, Cell differentiation, Neoplasm staging