Increased risk of colorectal neoplasia in inflammatory bowel disease patients with post-inflammatory polyps: A systematic review and meta-analysis

BACKGROUND: Inflammatory bowel disease (IBD) patients with post-inflammatory polyps (PIPs) may carry an increased risk of colorectal neoplasia (CRN) including dysplasia and cancer. Current guidelines recommend active colonoscopy follow-up for these patients. However, the evidence for guidelines is still poor. In addition, some recent high-quality reports present a different view, which challenges the current guidelines. We hypothesize that IBD patients with PIPs are at increased risk of CRN. AIM: To evaluate the risk of CRN in IBD patients with and without PIPs. METHODS: A systematic search of PubMed, Embase, Cochrane Library, and Web of Science was performed to identify studies that compared the risk of CRN in IBD patients with and without PIPs. In addition, we screened the reference lists and citation indices of the included studies. Quality assessment was performed using the Newcastle–Ottawa Scale. Pooled odds ratio (OR) was calculated using the random-effects model to explore the final pooled effect size of the included studies and determine whether PIPs increase the risk of CRN. Sensitivity analysis, subgroup analysis, and assessment of publication bias were performed to examine the sources of heterogeneity. RESULTS: Twelve studies with 5819 IBD patients, including 1281 (22.01%) with PIPs, were considered eligible for this meta-analysis. We found that IBD patients with PIPs were at an increased risk of CRN as compared to those without PIPs [OR 2.01; 95% confidence interval (CI): 1.43–2.83]. The results were similar when colorectal cancer was used as the study endpoint (OR 2.57; 95%CI: 1.69–3.91). Furthermore, the risk of CRN was still increased (OR 1.80; 95%CI: 1.12–2.91) when restricted to ulcerative colitis patients. Heterogeneity was high among the included studies (I² = 75%). Subgroup analysis revealed that the high heterogeneity was due to the study design. Sensitivity analysis showed that the main statistical outcomes did not essentially change after excluding any one of the included studies. No significant publication bias was found in the funnel plots. CONCLUSION: IBD patients with PIPs have an increased risk of CRN as compared with those without PIPs, which support the current guidelines. However, a high-quality randomized controlled trial is warranted.