Clinical Characteristics and Outcomes of Small Bowel Neoplasms in Crohn's Disease: A Case-Control Study

Background Patients with Crohn's disease (CD) who have ileal or any small bowel (SB) involvement are at increased risk of developing SB cancer. Due to the rarity of this complication of CD, we aimed to describe the clinical features, presentation, and of small bowel neoplasms (SBN) in patients with CD.Methods A case-control study was performed to include patients >= 18 years old with a diagnosis of CD with or without SBN at a single large referral center from January 1992 to May 2023. Patients were identified using bioinformatics and natural language processing tools, as well as anatomic pathology records. Two age- and sex-matched controls were identified for each case.Results In total, 54 patients with CD and SBN and 108 patients with CD without SBN were identified. Of the cases, most had ileal CD (55.6%) with stricturing (59.3%) phenotype. Median duration of CD prior to SBN diagnosis was 19.5 years. Nonpenetrating/nonstricturing behavior (odds ratio [OR], 9.23; 95% CI, 2.91-29.32; P = .0008) was significantly associated with an increased odds of SBN. History of tobacco use (OR, 0.27; 95% CI, 0.13-0.60; P = .0011) and IBD-associated colonic neoplasia (OR, 0.18; 95%, CI 0.4-0.85; P = .0303) were protective in development of SBN.Conclusions Nonpenetrating/nonstricturing CD appeared to raise SBN risk. History of tobacco use and colonic IBD-associated neoplasia are associated with reduced risk of SBN. Further studies with large sample sizes are needed to determine true incidence and risk factors associated with SBN in CD and assess potentially protective effects of early surgery. Nonpenetrating/nonstricturing and stricturing (only) Crohn's disease may be associated with increased odds of small bowel neoplasia, while penetrating disease did not seem to be a risk factor. History of tobacco use and inflammatory bowel disease-associated colorectal neoplasia showed reduced small bowel neoplasia risk.