Risk of Neoplasia After Colectomy in Patients With Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND & AIMS: Colorectal neoplasia can still develop after colectomy for inflammatory bowel disease. However, data on this risk are scare, and there have been few conclusive findings, so no evidence-based recommendations have been made for postoperative surveillance. We conducted a systematic review and meta-analysis to determine the prevalence and incidence of and risk factors for neoplasia in patients with inflammatory bowel disease who have undergone colectomy, including the permanent-end ileostomy and rectal stump, ileorectal anastomosis (IRA), and ileal pouch-anal anastomosis (IPAA) procedures. METHODS: We searched PubMed, Embase, Web of Science, and Cochrane Library through May 2014 to identify studies that reported prevalence or incidence of colorectal neoplasia after colectomy or specifically assessed risk factors for neoplasia development. Studies were selected, quality was assessed, and data were extracted by 2 independent researchers. RESULTS: We calculated colorectal cancer (CRC) prevalence values from 13 studies of patients who underwent rectal stump surgery, 35 studies of IRA, and 33 studies of IPAA. Significantly higher proportions of patients in the rectal stump group (2.1%; 95% confidence interval [CI], 1.3%-3.0%) and in the IRA group (2.4%; 95% CI, 1.7%-3.0%) developed CRC than in the IPAA group (0.5%; 95% CI, 0.3%-0.6%); the odds ratio (OR) for CRC in the rectal stump or IRA groups compared with the IPAA group was 6.4 (95% CI, 4.3-9.5). A history of CRC was the most important risk factor for development of CRC after colectomy (OR for patients receiving IRA, 12.8; 95% CI, 3.31-49.2 and OR for patients receiving IPAA, 15.0; 95% CI, 6.6-34.5). CONCLUSIONS: In a meta-analysis of published studies, we found the prevalence and incidence of CRC after colectomy to be less than 3%; in patients receiving IPAA it was less than 1%. Factors that increased risk of cancer development after colectomy included the presence of a residual rectum and a history of CRC. These findings could aid in development of individualized strategies for post-surgery surveillance.