Helicobacter pylori infection and esophageal cancer risk:An updated meta-analysis

AIM:To clarify the association between Helicobacter pylori(H.pylori)infection and the risk of esophageal carcinoma through a meta-analysis of published data.METHODS:Studies which reported the association between H.pylori infection and esophageal cancer published up to June 2013 were included.The odds ratios(ORs)and corresponding 95%CIs of H.pyloriinfection on esophageal cancer with respect to health control groups were evaluated.Data were extracted independently by two investigators and discrepancies were resolved by discussion with a third investigator.The statistical software,STATA(version 12.0),was applied to investigate heterogeneity among individual studies and to summarize the studies.A meta-analysis was performed using a fixed-effect or random-effect method,depending on the absence or presence of significant heterogeneity.RESULTS:No significant association between H.pylori infection and esophageal squamous cell carcinoma(ESCC)risk was found in the pooled overall population(OR=0.97,95%CI:0.76-1.24).However,significant associations between H.pylori infection and ESCC risk were found in Eastern subjects(OR=0.66,95%CI:0.43-0.89).Similarly,cytotoxin-associated gene-A(CagA)positive strains of infection may decrease the risk of ESCC in Eastern subjects(OR=0.77,95%CI:0.65-0.92),however,these associations were not statistically significant in Western subjects(OR=1.26,95%CI:0.97-1.63).For esophageal adenocarcinoma(EAC)the summary OR for H.pylori infection and CagA positive strains of infection were 0.59(95%CI:0.51-0.68)and 0.56(95%CI:0.45-0.70),respectively.CONCLUSION:H.pylori infection is associated with a decreased risk of ESCC in Eastern populations and a decreased risk of EAC in the overall population.