Association between Hepatitis B virus and gastric cancer: A systematic review and meta-analysis

An increasing number of studies are suggesting that hepatitis B virus (HBV) infection may be associated with an increased risk of not only hepatocellular carcinoma but also gastric cancer (GC). Whether HBV infection can be a risk factor for GC remains to be explored. In this study, we systematically searched for all eligible literature in 7 databases (China National Knowledge Infrastructure, WanFang, China Science and Technology Journal, PubMed, Cochrane Library, Web of Science and Embase). Eligible studies were required to have a case-control or cohort design. Sixteen studies were included and a meta-analysis was performed using Stata version 17.0. The quality of the included studies was assessed using the Newcastle-Ottawa Scale. The association between HBV infection and risk of GC was quantified by calculating the odds ratio and 95% confidence interval. The proportion of high- quality studies was 87.5% (14/16). The risk of GC was higher when HBV infection was present than when it was not (combined odds ratio 1.29, 95% confidence interval 1.16-1.44; I (2) = 62.7%, p < 0.001). The results of subgroup analyses were consistent with the main results. In conclusion, this systematic review and meta-analysis identified a positive association between HBV infection and an increased risk of GC.