Gallstones Are Associated with Colonic Adenoma: A Meta-analysis

Increased levels of secondary bile acids after gallstone disease and cholecystectomy are believed to increase the risk of colorectal cancer. It remains unclear whether there is a similar risk of developing adenomas. The aim of this meta-analysis was to determine the risk of developing colonic adenomas following gallstone disease or cholecystectomy. The study was based on a systematic search of PubMed, MEDLINE, EMBASE, and Current Contents (1950-2012). Selection criteria were developed to sort for studies exploring the relationship between cholelithiasis, cholecystectomy, and colonic adenoma in an adult population. A random-effects model was used to generate pooled odds ratios (OR) and 95 % confidence intervals (CI). Publication bias and heterogeneity were assessed. Of the 1,276 studies identified, 14 were suitable for final analysis. There were 253,059 subjects in total, 42,543 of whom were diagnosed with colonic adenoma, and 28,281 of whom had gallstones or underwent cholecystectomy. There was a significant risk of developing colonic adenoma if gallstones were present (OR = 2.26; 95 % CI = 1.83-2.81). A risk was also seen with cholecystectomy (OR = 1.15; 95 % CI = 1.04-1.26), but this risk was negated when only adjusted odds were selected (OR = 1.01; 95 % CI = 0.91-1.12). No publication bias and only low levels of heterogeneity existed. Gallstones increase the risk of colonic adenoma. No association exists with cholecystectomy.