Pancreatic cancer (Exocrine)

There are two distinct types of pancreatic cancer, differentiated by whether they arise from exocrine or endocrine tissue. By far the most common (up to 95 %) are neoplasms of the exocrine pancreas, and they are the focus of this discussion. Most exocrine pancreatic neoplasms (90 %) are adenocarcinomas, and three quarters of them arise in the head of the pancreas. Neoplasms of the endocrine pancreas are relatively rare and differ both biologically and clinically from exocrine cancers. Because they affect endocrine tissue, they often cause recognizable hormonal symptoms; thus, they are often detected at early stages and are more successfully treated. Exocrine pancreatic cancers, in contrast, do not cause early symptoms, and when symptoms appear, they are often vague in nature. By the time significant pain, jaundice, or weight loss is evaluated, disease is usually advanced, and as many as 80 % of patients present with disease defined as regionally advanced or metastatic on imaging studies.