No association between pseudopolyps and colorectal neoplasia in patients with inflammatory bowel diseases

Background & Aims: Patients with inflammatory bowel diseases who have postinflammatory polyps (PIPs) have an increased risk of colorectal neoplasia (CRN). European guidelines propose that patients with PIPs receive more frequent surveillance colonoscopies, despite limited evidence of this increased risk. We aimed to define the risk of CRN and colectomy in patients with inflammatory bowel diseases and PIPs. Methods: We conducted a multicenter retrospective cohort study of patients with inflammatory bowel diseases who underwent colonoscopic surveillance for CRN, from January 1997 through January 2017, at 5 academic hospitals and 2 large nonacademic hospitals in New York or the Netherlands. Eligible patients had confirmed colonic disease with duration of at least 8 years (or any duration, if they also had primary sclerosing cholangitis) and no history of advanced CRN (high-grade dysplasia or colorectal cancer) or colectomy. The primary outcome was occurrence of advanced CRN according to PIP status; secondary outcomes were occurrence of CRN (inclusive of low-grade dysplasia) and colectomy. Results: Of 1582 eligible patients, 462 (29.2%) had PIPs. PIPs were associated with more severe inflammation (adjusted odds ratio 1.32; 95% confidence interval [CI] 1.13–1.55), greater disease extent (adjusted odds ratio 1.92; 95% CI 1.34–2.74), and lower likelihood of primary sclerosing cholangitis (adjusted odds ratio 0.38; 95% CI 0.26–0.55). During a median follow-up period of 4.8 years, the time until development of advanced CRN did not differ significantly between patients with and those without PIPs. PIPs did not independently increase the risk of advanced CRN (adjusted hazard ratio 1.17; 95% CI 0.59–2.31). The colectomy rate was significantly higher in patients with PIPs (P =.01). Conclusions: In a retrospective analysis of data from 2 large independent surveillance cohorts, PIPs were associated with greater severity and extent of colon inflammation and higher rates of colectomy, but were not associated with development of any degree of CRN. Therefore, intervals for surveillance should not be shortened based solely on the presence of PIPs.