The Five Periampullary Cancers, not Just Different Siblings but Different Families: An International Multicenter Cohort Study

Cancer arising in the periampullary region can be anatomically classified in pancreatic ductal adenocarcinoma (PDAC), distal cholangiocarcinoma (dCCA), duodenal adenocarcinoma (DAC), and ampullary carcinoma. Based on histopathology, ampullary carcinoma is currently subdivided in intestinal (AmpIT), pancreatobiliary (AmpPB), and mixed subtypes. Despite close anatomical resemblance, it is unclear how ampullary subtypes relate to the remaining periampullary cancers in tumor characteristics and behavior. This international cohort study included patients after curative intent resection for periampullary cancer retrieved from 44 centers (from Europe, United States, Asia, Australia, and Canada) between 2010 and 2021. Preoperative CA19-9, pathology outcomes and 8-year overall survival were compared between DAC, AmpIT, AmpPB, dCCA, and PDAC. Overall, 3809 patients were analyzed, including 348 DAC, 774 AmpIT, 848 AmpPB, 1,036 dCCA, and 803 PDAC. The highest 8-year overall survival was found in patients with AmpIT and DAC (49.8