ObjectiveTo investigate the diagnostic value of serum alpha-fetoprotein (AFP) and regenerating islet-derived 4(REG4) levels in endometrial cancer (EC) and their relationship with lymph node metastasis.MethodsA total of 120 newly diagnosed EC patients admitted to our hospital from January 2021 to June 2023 were collected as the EC group. According to the status of lymph node metastasis, they were grouped into lymph node metastasis group (n=68) and non lymph node metastasis group (n=52). Another 80 patients with endometritis during the same period were selected as the benign lesion group, and 65 physically healthy persons were selected as the control group. ELISA was used to detect serum AFP and REG4 levels; Correlation between serum AFP and REG4 and the diagnostic value of both for EC were analyzed. Multivariate Logistic regression was applied to analyze the influencing factors of EC lymph node metastasis.ResultsThe serum AFP and REG4 levels were significantly higher in the benign lesion and EC groups than those in the control group (P<0.05), and serum AFP and REG4 levels were significantly higher in the EC group than those in the benign lesion group (P<0.05). Serum AFP and REG4 levels were positively correlated (r=0.205, P=0.025), and the combination of the two was more effective in diagnosing EC than the diagnosis alone (Z_{combination-AFP}=4.335, P<0.001, Z_{combination-REG4}=2.618, P=0.009). The serum AFP and REG4 levels in the lymph node metastasis group were significantly higher than those in the non lymph node metastasis group (P<0.05), and elevated serum AFP and REG4 levels were risk factors for EC lymph node metastasis.ConclusionSerum AFP and REG4 levels were significantly elevated in EC patients, both of which have some diagnostic value for EC and are associated with EC lymph node metastasis.