Objectives: Helicobacter pylori may reportedly be associated with extragastric malignancy beyond gastric cancer. The present study aimed to evaluate the association between H. pylori infection and colorectal neoplasia through a systematic review and meta-analysis.
Methods: The literature search aimed to retrieve all relevant studies published up to September 2019 that examined the risk for colorectal neoplasia including colorectal adenoma, advanced adenoma, and cancer in patients with H. pylori infection. Meta-analysis was performed to calculate pooled odds ratios (ORs) with corresponding 95% confidence intervals (CIs). If publication bias was observed, the pooled OR was adjusted using the trim-and-fill method.
Results: Forty-eight studies including 171,045 patients were evaluated, of which 24, 8, and 31 reported H. pylori-associated risk for adenoma, advanced adenoma, and cancer, respectively. H. pylori infection was associated with a significantly higher risk for colorectal adenoma (pooled OR 1.49 [95% CI 1.37-1.62]). H. pylori infection was also associated with a higher risk for advanced colorectal adenoma (pooled OR 1.50 [95% CI 1.28-1.75]). The risk for colorectal cancer in patients with H. pylori infection was also identified (pooled OR 1.44 [95% 1.26-1.65]). Although publication bias was identified in the analysis for colorectal adenoma, the pooled estimate was not significantly changed after adjustment (pooled OR 1.39 [95% CI 1.27-1.52]).
Discussion: Although this meta-analysis based on the observational studies could not show causality, it demonstrated that colorectal adenoma, advanced adenoma, and cancer were all associated with H. pylori infection.