Cancer risk after resection of polypoid dysplasia in patients with longstanding ulcerative colitis: a meta-analysis

American and European guidelines propose complete endoscopic resection of polypoid dysplasia (adenomas or adenoma-like masses) in patients with longstanding colitis, with close endoscopic follow-up. The incidence of cancer after detection of flat low-grade dysplasia or dysplasia-associated lesion or mass is estimated at 14 cases/1000 years of patient follow-up. However, the risk for polypoid dysplasia has not been determined with precision. We investigated the risk of cancer after endoscopic resection of polypoid dysplasia in patients with ulcerative colitis. MEDLINE, EMBASE, PubMed, and the Cochrane library were searched for studies of patients with colitis and resected polypoid dysplasia, with reports of colonoscopic follow-up and data on cancers detected. Outcomes from included articles were pooled to provide a single combined estimate of outcomes by using Poisson regression. Of 425 articles retrieved, we analyzed data from 10 studies, comprising 376 patients with colitis and polypoid dysplasia with a combined 1704 years of follow-up. A mean of 2.8 colonoscopies were performed for each patient after the index procedure (range, 0-15 colonoscopies). The pooled incidence of cancer was 5.3 cases (95% confidence interval, 2.7-10.1 cases)/1000 years of patient follow-up. There was no evidence of heterogeneity or publication bias. The pooled rate of any dysplasia was 65 cases (95% confidence interval, 54-78 cases)/1000 patient years. Patients with colitis have a low risk of colorectal cancer after resection of polypoid dysplasia; these findings support the current strategy of resection and surveillance. However, these patients have a 10-fold greater risk of developing any dysplasia than colorectal cancer and should undergo close endoscopic follow-up