Non-pancreatic periampullary adenocarcinomas: An explanation for favorable prognosis

Background/Aims: Our previous studies demonstrate that patients with non-pancreatic periampullary adenocarcinomas have a favorable prognosis relative to those with pancreatic adenocartinoma. This study investigates histopathologic factors that contribute to the superior outcome of these patients. Methodology: A retrospective review of all patients explored for periampullary neoplasms at a single institution over a 20-year period. Results: 291 patients with periampullary neoplasms underwent exploratory laparotomy, of which 186 had resectable tumors. Periampullary adenocarcinomas were resected in 120: pancreatic head (n=74), distal common bile duct (n=10), duodenum (n=5), and ampulla of Vater (n=31). The resection rate for non-pancreatic adenocarcinomas was 90%, while that of pancreatic cancers was 44% (p<0.01). Median survival for resected non-pancreatic adenocarcinomas was 38.8 months; that of pancreatic tumors was 15.3 months (p<0.01). Non-pancreatic adenocarcinomas were significantly smaller (p<0.001), better differentiated (p<0.001), and less likely to have involved nodes (p<0.001), margins (p<0.001), perineural invasion (p<0.001), or vascular invasion (p<0.2) than pancreatic adenocarcinomas. Conclusions: Histopathologic features of non-pancreatic periampullary adenocarcinomas significantly differentiate them from pancreatic adenocarcinoma and contribute to their relatively favorable long-term outcome following resection.