Incidence rates of exocrine and endocrine pancreatic cancers in the United States

Descriptive studies of pancreatic cancer incidence have been sparse particularly in terms of tumor histology and stage. The purpose of this study was to examine the incidence rate trends of exocrine and endocrine pancreatic cancers by demographic and tumor characteristics using data from the Surveillance, Epidemiology, and End Results (SEER) program from 1977 to 2005. During this period, the incidence of exocrine pancreatic cancer generally decreased whereas the incidence of endocrine pancreatic cancer increased. This difference in trends by histology was evident across age, gender, and racial groups. It was also evident among different racial/ ethnic groups using data from 1992 to 2005. Variation in trends was observed by stage. The incidence of exocrine cancers declined for all stages except regional. Endocrine cancer incidence increased for all tumor stages, and the increase was most prominent for localized tumors. When exocrine tumors were stratified by tumor subsite, the incidence of cancers in the tail and body regions increased while the incidence in other regions decreased. While better detection and classification of tumors through improved diagnostic procedures may be related to these changing trends, etiologic factors warrant study.