Pancreatic cancer (PC) has the highest case-fatality rate of any of the major cancers, both in the US and worldwide. The disease is difficult to detect, rapidly metastatic, resistant to treatment, and often results in death. Pancreatic adenocarcinoma is also one of the most difficult cancers to study. Case-control studies may be inaccurate because patients with PC often die within weeks of their diagnosis. At the same time, prospective studies of PC are challenging due to the relative rarity of this type of cancer (~ 1% lifetime risk) and low prevalence due to short life expectancy. Consequently, PC etiology is often investigated by analyzing data from large-scale prospective studies or clinical trials for diseases other than PC, but limited numbers of cases and methodological heterogeneity (e.g., no or incomplete histological verification) affect the validity of these results.
The etiology of PC is widely acknowledged to be multi-factorial. The incidence of PC is greater in males than in females, and higher in Blacks than Whites. According to SEER 17 areas data, the age-adjusted incidence of PC in 2006 per 100,000 individuals was 11.61 (95%CI 11.34-11.88) for Whites and 15.57 (95%CI 14.57-16.62) for Blacks, with 16.56 for Black men (95% CI 15.08-18.61). Environmental or host risk factors shown to be associated with PC include cigarette smoking, obesity, type II diabetes mellitus, chronic pancreatitis, physical inactivity and blood groups A or B. Dietary risks may be related to low fruit and vegetable intake and increased intake of high-heat cooked meats (i.e., grilled/fried animal protein sources). Two separate, recent studies linked pancreatic cancer to high consumption of carbohydrates and alcohol. Unfortunately, these common risk factors have small effect sizes, so it is difficult to produce highly accurate risk models. For example, smoking yields a risk ratio of approximately 2. The risk of developing PC is recognized as being exceptionally elevated in certain genetically predisposed families (e.g., hereditary pancreatitis,), but only about 10% of all PC cases can be attributed to genetic causes.
Because of these challenges, a number of groups have dedicated themselves to pancreatic cancer research efforts. Consider joining advocacy groups such as the National Pancreas Foundation to help with the fight.