Medical risk factors for small-bowel adenocarcinoma with focus on Crohn disease: A European population-based case-control study

Background: Crohn disease and biliary diseases have been associated with sm all-bowel adenocarcinoma (SBA). We examined how medical conditions affect t he risk of SEA. Methods: A population-based European multicentre case-contr ol study during the period 1995-97 including 95 histologically verified cas es of SEA along with 3335 population controls; 70 cases (74%) and 2070 (62% ) controls were interviewed about previous medical conditions. Results: Cro hn disease was identified in two SEA cases (both located in ileum) and two controls; odds ratio (OR) 53.6 (6.0-477) (95% CI in parentheses). Only one case and no controls had had long-standing Crohn disease. Coeliac disease w as associated with SEA (2 cases, 0 controls), but one of the cases was diag nosed at the same time as the SEA. Overall, people with a history of gallst ones had no increased risk of SEA. The OR was exclusively increased during the 3-year period preceding the SEA diagnosis. Previous gallstone surgery, which may be a sign of severs gallstone disease, was not associated with SE A. Liver cirrhosis, hepatitis or medical treatments with radioactive substa nces or corticosteroid tablets were not associated with this disease. Cases with SEA had an increased prevalence of anaemia; OR 15.3 (2.5-92.1). An as sociation between low educational level and SEA was found; OR 1.75 (1.0-3.0 ). Conclusion: This study supports Crohn disease and coeliac disease being strong but rare risk factors for SEA. Previous gallstones were unrelated to SEA, and detection bias may account for the findings in earlier studies.