Epidemiology of pancreatic cancer: an overview.

Pancreatic cancer, although infrequent, has an exceptionally high mortality rate, making it one of the four or five most common causes of cancer mortality in developed countries. The incidence of pancreatic cancer varies greatly across regions, which suggests roles for lifestyle factors, such as diet, or environmental factors, such as vitamin D exposure. Smoking is the most common known risk factor, and is the cause of 20-25% of all pancreatic tumors. Alcohol does not seem to be a risk factor, unless it leads to chronic pancreatitis, which is a probable risk factor. Long-standing diabetes increases the risk of pancreatic cancer, but can also be an early manifestation of pancreatic tumors. 5-10% of patients with pancreatic cancer have an underlying germline disorder, while the remaining percentage of cancer cases is thought to be caused by somatic mutations. Some individual studies suggest that mutations in various polymorphic genes can lead to small increases in the risk of pancreatic cancer, but these findings need to be replicated. Rising prevalence of smoking in developing countries, improved diagnosis and increasing population longevity are all likely to increase the global burden of pancreatic cancer in the coming decades.