Tissue Claudin 18.2 levels as a prognostic factor in gastric adenocarcinomas: A retrospective cohort study

Gastric cancer continues to be a worldwide health crisis because it results in many deaths. The protein Claudin 18.2 (CLDN18.2) exists at higher levels in gastric adenocarcinoma tumors which makes it a promising therapeutic target. This study evaluated CLDN18.2 protein levels in gastric cancer tissues and their relationship with patient and tumor characteristics. This retrospective cohort study analyzed 112 gastric adenocarcinoma patients together with 62 healthy controls. The research team used ELISA to determine CLDN18.2 concentrations in tumor tissue and adjacent normal tissue and control specimens. Patients were stratified based on their Helicobacter pylori infection status, tumor site, tumor grade, and presence of metastasis. Diagnostic performance was assessed using receiver operating characteristic analysis, and Cox regression analysis was performed to evaluate prognostic factors for survival. The cancer tissue contained elevated CLDN18.2 levels which measured at 2.385 ng/mL (median), whereas normal tissue and controls displayed 1.349 ng/mL and 1.260 ng/mL (median) respectively (P < .001). The receiver operating characteristic analysis for diagnosing gastric adenocarcinoma showed 92.4% sensitivity and 100% specificity at 1.675 ng/mL (area under the curve: 0.956). The study found that CLDN18.2 levels were higher in patients with Helicobacter pylori infection and in cases with poor tumor differentiation and metastasis. The risk of metastasis increased by 4.82 times for every 1 ng/mL rise in CLDN18.2 levels (P < .001). This study demonstrates that CLDN18.2 exhibits strong diagnostic performance for gastric adenocarcinoma and shows strong correlation with cancer progression. The Cox regression analysis established CLDN18.2 as an independent prognostic factor for patient survival outcomes.