单中心494例胃癌Claudin18.2表达特点及与临床病理特征的相关性OA

Objective To investigate the expression characteristics of Claudin18.2 in gastric cancer and its rela-tionship with clinicopathological characteristics.Methods 494 gastric adenocarcinoma samples were collected from the Pathology Department of China-Japan Friendship Hospital from November 2020 to October 2024.Pathological re-sults were diagnosed according to WHO and Lauren classification.The expression of Claudin18.2,mismatch repair proteins(MLH1,MSH2,MSH6,PMS2),HER2,and PD-L1 was detected by EnVision method.Twenty cases of the remaining gastric tissues(normal gastric mucosa)were taken as the control group.Results With reference to the 2024 NCCN guidelines(the 5th edition)for gastric cancer,75%was taken as the positive cut-off value.The positive rates of Claudin18.2 in biopsy and surgery specimens were 20.91%(46/220)and 27.01%(74/274),respectively.The normal gastric mucosa in the control group showed moderate to strong positive expression of Claudin18.2.Among 274 surgical specimens,the positive rate of mismatch repair defect group(6.25%)was significantly lower than that of proficient mismatch repair group(29.75%),and the difference was statistically significant(P<0.05).Further-more,numerically higher positive rates of Claudin18.2 were observed in subgroups including males,age<65 years,proximal tumor location,maximum tumor diameter<5.0 cm,high differentiation,Lauren mixed type,TNM stageⅡ,HER2 2+,PD-L1 positive status,and absence of lymph node metastasis.However,none of these differences reached statistical significance(P>0.05).To further clarify the independent predictive value of MMR status,we conducted multivariate logistic regression analysis,and the results indicated that MMR status was an independent pre-dictive factor for Claudin18.2 expression(P=0.004).Conclusion The positive rate of Claudin18.2 in gastric can-cer surgical specimens was higher than that in biopsy specimens.The expression of Claudin 18.2 is significantly corre-lated with mismatch repair defect but shows no significant association with other clinicopathological characteristics.