Auxiliary diagnosis of periampullary carcinomas by comprehensive next-generation sequencing.

Abstract

e16221 Background: Periampullary carcinoma, originating from ampulla, head of pancreas, common bile duct and duodenum, is a group of highly heterogeneous tumors with similar clinical presentations and anatomical sites but totally different prognosis. This study aims to investigate the potential diagnostic value of molecular testing in patients with periampullary carcinomas. Methods: This study retrospectively recruited patients diagnosed with periampullary, common bile duct, head of pancreas and duodenum cancers whose tumor tissue or circulating free DNA samples were sent to perform parallel hybridization-based next-generation sequencing of cancer-related genes ranging from 59 to 1021. Differentiated mutated genes were compared between different cancers using Fisher’s exact test and p < 0.05 was significant. Results: A total of 199 patients were enrolled in this molecular analysis, including 74 periampullary carcinomas, 43 duodenal cancers, 31 cancers of the common bile duct and 51 pancreatic head carcinomas. The top five most commonly mutated genes in these cancers were listed in the table. Fisher’s exact test suggested that ARID1A and LRP1B mutations were more frequently identified in duodenal cancer compared to periampullary cancer (p = 0.016 and 0.010, respectively). Compared to common bile duct carcinoma, periampullary cancer had more APC mutations and less ERBB3 mutations (p = 0.017 and 0.027, respectively). Strikingly, there was no APC mutation identified in pancreatic head cancer. Conclusions: Many common mutations were detected in periampullary, common bile duct, head of pancreas and duodenum cancers, such as TP53, KRAS and CDKN2A. However, APC mutation was not detected in pancreatic head carcinoma that is characterized by the worst prognosis. Genetic testing may facilitate distinguish the prognosis of periampullary carcinoma and assist in the differential diagnosis of pancreatic head carcinoma.[Table: see text]