Small Bowel Cancer: Scoping Out a Rarity

medscape


Medscape: What predisposing factors are associated with an increased risk for small bowel adenocarcinoma? 
 
Michael J. Overman, MD: There are three big factors. The first is hereditary nonpolyposis colorectal cancer (HNPCC), or Lynch syndrome, which predisposes not only to colorectal cancer but also to a number of other cancers, including small bowel adenocarcinoma. The second is inflammatory bowel disease (IBD), particularly Crohn's disease; these patients can have involvement of the distal small bowel (ileal adenocarcinoma). Celiac disease would be the third factor. Celiac disease is a gluten-associated enteropathy in which you have an autoimmune attack against gluten in your diet. You'll have inflammation in the epithelial lining of your small bowel as your body reacts to the gluten in your diet, and that inflammation can lead to an increased risk for small bowel adenocarcinoma. Those are the big three predisposing factors. However, the majority of small bowel adenocarcinomas, approximately 70%, are sporadic and have unclear factors associated with them.