The epidemiology of pancreatic cancer in the United States, 1995–2000

Purpose Cancer of the pancreas is considered synonymous with exocrine adenocarcinomas of the pancreas, and many analyses of epidemiologic data have not distinguished between exocrine and endocrine neoplasms. This is the largest population-based descriptive epidemiologic study on pancreatic cancer covering 67% of the U.S. population, and evaluating the complete distribution of morphologic types of exocrine and neuroendocrine pancreatic cancers. Methods The North American Association of Central Cancer Registries (NAACCR) made available for analysis a research data set covering the six years, 1995–2000. This data represents 103,398 invasive pancreatic cancers diagnosed in the United States, and includes 89,756 whites (87%), 10,365 blacks (10%), and 2,771 Asians or Pacific Islanders (3%). A detailed examination was conducted of the distribution of pancreatic cancer cases by age, race, sex, stage, and pancreatic subsite, and by exocrine and neuroendocrine histologic groups. The distribution of subtypes of exocrine and neuroendocrine histologic groups was further analyzed by pancreatic subsite in order to describe tumor origin. Results 94% of all microscopically confirmed pancreatic cancers were of exocrine origin. 3.5% of all microscopically confirmed pancreatic cancers were of neuroendocrine origin. Neuroendocrine carcinoma and “other neuroendocrine” (1.7% of the total number of microscopically confirmed cases) was the largest subtype within the Neuroendocrine Group. It consisted of 1,267 neuroendocrine carcinomas, 1 merkel cell carcinoma, and 1 apudoma. Islet cell (1.1%) was the next largest subtype. Combined with the other islet subtypes (insulinomas, glucagonomas, gastrinomas, and VIPomas), “islet cell carcinomas” made up 1.3% of the total number of microscopically confirmed cases. Conclusion This study allows one to evaluate the entire spectrum of morphologic types diagnosed in the U.S. population, not just the most common histologic groups. This is an important consideration given that survival is influenced not only by stage of diagnosis, but by histologic type.