Small Bowel Adenocarcinoma: Is There a Difference in Survival for Crohn's Versus Sporadic Cases?

Background and Aims: It is well known that Crohn's disease is a risk factor for the development of small bowel adenocarcinoma. However, the association between Crohn's disease-associated small bowel adenocarcinoma and survival is less understood. The goal of this study was to determine the impact of Crohn's disease on survival in small bowel adenocarcinoma. Methods: Patients with small bowel adenocarcinoma, either associated with Crohn's disease or diagnosed sporadic, were identified in the National Cancer Database from 2004-2016.The primary outcome was overall survival. Results: Of 2668 patients, 493 had Crohn's disease-associated small bowel adenocarcinoma and 2175 had sporadic small bowel adenocarcinoma. Crohn's disease patients were more likely to present at a younger age [62 vs 65, p< 0.001], have tumours located in the ileum [62.7% vs 25.0%, p < 0.001], and have poorly differentiated tumours [47.0% vs 31.7%, p < 0.001] compared with sporadic small bowel adenocarcinoma. Factors associated with significantly decreased survival included older age (hazard ratio [HR]: 1.02, 95% confidence interval [CI]: 1.02-1.03, p < 0.00)], higher Charlson score [HR: 1.39, 95% CI: 1.13-1.72, p = 0.002], higher tumour grade [HR: 1.09, 95% CI: 1.04-1.14, p < 0.001], positive surgical margins [HR: 1.60, 95% CI: 1.39-1.84, p < 0.001], and higher stage of disease [HR: 1.90, 3.75, 8.13, 95% CI: 1.37-2.64, 2.68-5.24, 5.77-11.47, for II, III, IV, respectively, compared with I, all p < 0.001]. Receipt of chemotherapy was associated with significantly improved survival [HR: 0.61, 95% CI: 0.53-0.70, p < 0.001]. Crohn's disease [HR: 1.01, 95% CI: 0.99-1.02, p= 0.39], was not significantly associated with survival. Conclusion: Compared with sporadic patients, Crohn's disease patients have similar overall survival, and Crohn's disease is not an independent risk factor for mortality.