APC and small intestine carcinoma: Small bowel cancer is <5% in GI tract cancers and has mildly increased in recent years,[19,36] with 50% of adenocarcinomas of the small intestine in the duodenum.[37] An animal study has shown that unconjugated bile acids contribute to peri-ampullary tumor formation in the setting of an Apc mutation.[38] This study reveals that BTI patients do not have increased risk of small bowel cancer.