Molecular pathogenesis of pancreatic cancer.

Our understanding of the biology of pancreatic carcinoma has greatly benefited from studies of the genetic alterations in this tumor type. The p16-CDK4-cyclinD-Rb pathway, the p53 tumor suppressor pathway, and the DPC4/Smad4 pathway are genetically inactivated in the majority of sporadic pancreatic carcinomas, whereas oncogenic K-ras signaling is almost ubiquitously activated. These genetic data have provided the basis to shape a first genetic progression model of this tumor type. Furthermore, a number of well defined genetic syndromes which are associated with an inherited risk for pancreatic carcinoma have been identified recently.