Association betweenHelicobacter pyloriinfection and the risk of colorectal cancer A systematic review and meta-analysis

Background: The existing evidence on the relationship betweenHelicobacter pyloriinfection and the risk of colorectal cancer is inconsistent. We conducted a systematic review with a meta-analysis to explore this relationship and to determine whether the relationship varies according to the study characteristics. Methods: We searched the PubMed, OVID, EMBASE database, and the reference lists of pertinent articles published up to October 2019 by 2 researchers independently. Summary odds ratios (OR) with their 95% confidence intervals (CIs) were estimated using a random-effects model. Results: Forty seven studies including 17,416 cases of colorectal cancer (CRC) and 55,811 cases of control were included. Overall,H. pyloriinfection was associated with an increased risk of CRC (OR = 1.70 95% CI 1.64-1.76,I-2 = 97%), although there was significant heterogeneity among the studies. Subgroup analysis revealed that the positive correlation might vary by the design of study conducted. Conclusion: This meta-analysis demonstrates a positive association betweenH. pyloriinfection and the risk of colorectal cancer.