Increased Colorectal Neoplasia Risk in Patients with Inflammatory Bowel Disease and Serrated Polyps with Dysplasia.

Background: The impact of serrated polyps on the advanced colorectal neoplasia (CRN) risk in inflammatory bowel disease (IBD) patients is unknown. Serrated polyps are histologically categorized as hyperplastic polyps (HPs), sessile serrated lesions (SSLs), and traditional serrated adenomas (TSAs).

Aims: We aimed (1) to characterize the serrated polyps in IBD patients, (2) to identify factors associated with the presence of serrated polyps in IBD, and (3) to assess the CRN risk in IBD patients with serrated polyps.

Methods: We established a retrospective cohort of IBD patients with and without colonic serrated polyps. Cox-regression analysis with time-dependent variables was used to compare advanced CRN risk in IBD patients with and without serrated polyps.

Results: Of the 621 enrolled IBD patients, 198 had a serrated polyp (92 HPs, 88 SSLs without dysplasia, 13 SSLs with dysplasia, and 5 TSAs). Independent factors associated with serrated polyps were ulcerative colitis (UC) (odds ratio (OR) 1.77, 95% confidence interval (CI) 1.19-2.62, p = 0.005), male gender (OR 1.63, 95% CI 1.11-2.40, p = 0.013), and older age (per year increase, OR 1.06, 95%CI 1.05-1.08, p < 0.001). TSAs and SSLs with dysplasia were risk factors for subsequent advanced CRN (HR 13.51, 95% CI 3.11-58.68, p < 0.001), while HPs (HR 1.98, 95% CI 0.46-8.60, p = 0.36) and SSLs without dysplasia (HR 0.87, 95% CI 0.11-6.88, p-0.89) did not impact the subsequent advanced CRN risk.

Conclusions: UC, male gender and older age were associated with the presence of serrated polyps. The majority of serrated polyps (91%) were HPs and SSL without dysplasia and did not affect the CRC risk. However TSAs and SSLs with dysplasia, representing a small subgroup of serrated polyps (9%), were associated with subsequent advanced CRN.