Epidemiology and risk factors for pancreatic cancer.

Pancreas cancer is considered an 'orphan' cancer because of its relative low incidence. Unfortunately even with early diagnosis, mortality rates are high, explaining why, despite the low incidence, it ranks eighth in a world listing of cancer mortality. International incidence rates vary in different countries, implying that environmental factors are important. Of these factors, smoking is the most well documented etiologic agent, explaining about 25% of all cases. Dietary factors may be important, but it has been difficult to define specific items which either increase or decrease the risk of pancreatic cancer. Since the incidence of pancreas cancer is so strongly age-dependent, we can anticipate an increasing number of patients as the population of most Western countries ages.