Endoscopic image of adenocarcinoma of duodenum seen in the post-bulbar duodenum.

A study of small intestine cancer patients reported that alcohol consumption was associated with adenocarcinomas and malignant carcinoid tumors.

"In men and women combined, a significant 3-fold increased risk in heavy drinkers (80+g ethanol/day) relative to more moderate drinkers and non-drinkers was observed."

"Alcohol and tobacco consumption did not increase the risk of adenocarcinoma of the small intestine. … While the present data are inconsistent with a major effect of tobacco or alcohol, a moderate association between these factors and small bowel cancer may have been obscured by the play of chance."