Combined detection of Helicobacter pylori and Claudin18.2 for risk stratification of gastric precancerous lesions in a county-level screening system.

OBJECTIVE: To evaluate whether combined detection of Helicobacter pylori (HP) infection and Claudin18.2 (CLDN18.2) expression improves risk stratification of gastric precancerous lesions within a county-level gastric cancer screening system. METHODS: A total of 1,642 high-risk individuals who underwent gastroscopy and pathological examination within the Deqing County Medical Community screening system from March 2022 to February 2024 were included. Immunohistochemistry was used to detect HP infection and CLDN18.2 expression. Gastric precancerous lesions were defined as the primary outcome. Associations were analyzed using χ2 test and multivariate logistic regression analysis, and the combined effects of the two markers were evaluated. RESULTS: The gastroscopy completion rate was 86.60%. A total of 391 cases of gastric precancerous lesions (23.81%) and 14 cases of early gastric cancer (0.85%) were detected. Age, history of chronic gastritis, HP infection, and CLDN18.2 positivity were independent risk factors (all p < 0.001). Combined analysis revealed a significant dose-response relationship, and the risk of precancerous lesions increased in proportion to the number of positive markers (P for trend < 0.001). CONCLUSION: Within a county-level screening framework, HP infection and CLDN18.2 expression are independently correlated with gastric precancerous lesions. Their combined detection improves risk stratification and may support more precise and efficient gastric cancer screening strategies.