Carcinomas of the pancreas, gallbladder, extrahepatic bile ducts, and ampulla of vater share a field for carcinogenesis: a population-based study.

Context: Carcinomas co-occur in the pancreas, extrahepatic bile ducts, and ampulla of Vater. We investigated whether cancers originating in these sites represent a field effect similar to that observed in the lung and upper aerodigestive tract.

Objective: To determine whether a field effect for carcinogenesis exists in the ampulla of Vater, extrahepatic bile ducts, gallbladder, and pancreas.