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

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.

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.

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.

Compared with sporadic patients, Crohn's disease patients have similar overall survival, and Crohn's disease is not an independent risk factor for mortality.