Epidemiology of pancreatic cancer

In the United States the incidence of and mortality from pancreatic cancer have increased over the past several decades but have tended to level off in recent years. The rates are higher in blacks than in whites and higher in males than in females. Mortality rates increase with age but there appears to be a decline in elderly blacks, possibly on an artifactual basis. There is a suggestion that rates are higher in Jews. No consistent differences by socioeconomic status or by geographic location within the United States have been identified. Both genetic and environmental factors may be playing significant roles in this disease. Cigarette smoking may be etiologically related, or at the very least, may help to identify a group of patients at increased risk of pancreatic cancer. However, the relative risk estimated for cigarette smoking is much lower than that found for cancer of the lung. The leveling off in incidence and mortality rates for pancreatic cancer in recent years also differs from the time trends observed for lung cancer. However, this could result from differences in site-specific carcinogens and from the fact that the lung is the first organ to be exposed to cigarette smoke in the highest concentrations and prior to the metabolism of any of its components. Dietary factors may have an important role in pancreatic cancer, but further research is needed to clarify this relationship. In particular, the possibility that dietary fats may be implicated and that vitamins or fiber may be protective in this disease remains to be explored. Finally, there is suggestive evidence that specific chemical exposures may be carcinogenic for the pancreas. Many of the data are from animal studies, and the findings from human studies are not entirely consistent.