A Clinicopathologic Comparison Between Early-Onset and Late-Onset Small Bowel Adenocarcinoma: A Multicenter International Study

Introduction: Early-onset small bowel adenocarcinoma (EO-SBA) is a rare and poorly characterized entity. Methods: This retrospective study conducted on an international multicenter cohort of 208 patients with SBA aimed at comparing clinicopathologic features of EO-SBA (age younger than 50 years at SBA diagnosis) and late-onset SBA (age 50 years or older at SBA diagnosis). Results: The presence of predisposing pathologic conditions was significantly more common in the EO-SBA group compared with that in the late-onset SBA group ( P = 0.003, Fisher exact test; relative risk: 1.50, 95% confidence interval: 1.20-1.86). This difference is mainly due to the significantly higher prevalence of celiac disease among patients with EO-SBA. Discussion: EO-SBA is strongly associated with predisposing conditions, particularly with celiac disease, highlighting the importance of routine screening for celiac disease in patients with EO-SBA.