Meta-analysis Of Association Between Epstein-Barr Virus Infection And Expression Of Programmed Immune Cell Death Ligand-1 In Gastric Cancer

Objective:Meta-analysis system was used to evaluate the relationship between EBV infection and the expression levels of PD-L1 in cancer cells and immune cells in gastric cancer tissues.Methods:By searching PubMed,Web of Science and other databases,Chinese and English literatures on the relationship between PD-L1 expression in gastric cancer tissues and EBV infection were collected,and multiple screening was conducted for the literatures.In addition,the reference list of selected articles was manually checked to obtain other possibly related articles.Data were extracted from the finally included literatures,and Rev Man 5.4 software was used for data analysis.Odds ratio(OR)and 95% Confidence interval(CI)were used for data analysis.CI)to evaluate the correlation between EBV infection and the expression of PD-L1 in cancer cells and immune cells in gastric cancer tissues.Results:Literature retrieval results: 1.The retrieved from the database related paper 672,after rejecting a duplicate paper 198,the two researchers by reading the title and abstract,discuss and after eliminating irrelevant and unable to get the full text of literature,selected 32 articles,by reading the full text,again to eliminate failed to extract the complete data of literature,eventually into 10 studies,all are English literature,in the country in China,the United States,Japan,Germany,Italy,Brazil and other countries.A total of 3752 subjects were included,all of whom were pathologically diagnosed as gastric cancer.The expression of PD-L1 was detected by immunohistochemistry,and EBV infection was determined by in situ hybridization.Among them,10 studies clearly analyzed and explored the relationship between the expression of PD-L1 in gastric cancer tissues and the infection status of EBV.2.Statistical analysis results:(1)The expression of PD-L1 in EBV positive and negative gastric cancer cells was statistically significant(OR=5.86,95% CI:4.37～7.85,P<0.0001),suggesting that the increased expression of PD-L1 in gastric cancer cells was associated with EBV infection.(2)There was a statistically significant difference in the expression of PD-L1 between the positive and negative EBV groups(OR=14.20,95%CI:8.59～23.49,P<0.00001),suggesting that the increased expression of PD-L1 in immune cells was associated with EBV infection.3.Sensitivity analysis and publication bias results: The sensitivity analysis indicated that the results in this meta-analysis were stable.The funnel chart is used to evaluate the publication bias of the included literature,and there is no obvious publication bias.Conclusion:The expression level of gastric cancer cells and immune cells PD-L1 in gastric cancer tissues was positively correlated with EBV infection,which may provide a new idea for the treatment of EBV associated gastric cancer.