Pancreatic cancer is usually a cancer of older people (average age of patients is 71 years), however some patients can develop cancer at an early age, such as 40. Incidence varies by race, gender, and geography. The disease occurs more often in African Americans than in whites and in men more than in women; global incidence rates vary approximately 30-fold. African Americans have the highest pancreatic cancer rate in the world. The reason for these risk factors is not yet known. There are four clear risk factors for pancreatic cancer: family history, cigarette smoking, long-standing diabetes, and hereditary and chronic pancreatitis.
- Cigarette Smoking: This risk factor is associated with approximately 25 percent of pancreatic cancers. People who smoke for twenty years or more have double the risk of those who have never smoked. Smoking has an even greater effect in families that inherit pancreatic cancer---increasing the odds of developing cancer by up to 7 fold and patients who smoke tend to develop cancer at an earlier age. This cancerous effect of smoking is also seen in patients with chronic pancreatitis or hereditary pancreatitis.
- Family History: Pancreatic cancer runs in families, and people in affected families have about a three-fold risk compared with the general population. About five percent of patients with pancreatic cancer report a family history of the disease. Hereditary syndromes would be seen in families that inherit pancreatic cancer along with other additional cancers. Examples of these additional cancers include: cancers of the colon, breast, lung, bladder, uterine, and melanoma. In addition to the families that inherit cancer, some families inherit chronic inflammation of the pancreas (hereditary pancreatitis); these patients are prone to developing pancreatic cancer. Many families simply inherit pancreatic cancer, with no other cancers in the family and no history of pancreatitis.
- Long-Standing Diabetes: There is about a two-fold increase in risk of pancreatic cancer among people who were diagnosed with diabetes as adults. This observation suggests that diabetes may be an independent risk factor for pancreatic cancer, as well as a possible consequence of the disease. The mechanism involved, however, is unclear.
- Pancreatitis: Pancreatic cancer risk among individuals with hereditary pancreatitis or nonhereditary chronic pancreatitis is about 50 times and 16 to 20 times higher, respectively, than those without pancreatitis. Studies also have implicated a number of other factors, including diet and nutrition, heavy alcohol consumption, other medical conditions, and certain occupational exposures, but these findings have been inconsistent.
- Magnetic Resonance Imaging (MRI): Magnetic Resonance Imaging (MRI) is a powerful magnet linked to a computer. The MRI machine is very large, with space for the patient to lie in a tunnel inside the magnet. The machine measures the body's response to the magnetic field, and the computer uses this information to make detailed pictures of areas inside the body. The information gained is similar to the information gained at ERCP, except that it is not quite as sensitive in picking up very small changes. Samples of the tumor can not be obtained at this procedure.
- Diet and Nutrition: Fruit and vegetable intake may have a protective effect against pancreatic cancer. The effect appears to be stronger for vegetables, particularly cruciferous vegetables. Folate is a nutrient is associated with a lower risk of panreatic cancer. Folate can be found in leafy green vegetables. Increased risk has been associated with high intake of meat, fat, and carbohydrates and with elevated body mass index and caloric intake. A recent study found an interaction between body mass index and caloric intake, suggesting that caloric intake in excess of that required to maintain energy balance (e.g. being overweight) may increase risk.
- Alcohol: Alcohol consumption at the level typically consumed by the U.S. population does not appear to increase risk; however, approximately 10 studies have reported an increased risk associated with heavy alcohol consumption.
- Occupational Exposures: Organochlorine compounds (DDT, DDE, and PCBs) have been associated with elevated risk in a small number of studies. Dry cleaning workers have an increased risk of pancreatic cancer, possibly due to exposure to chlorinated hydrocarbon solvents.
- Prevention: Smoking cessation appears to reduce risk. A few recent studies suggest that risk may revert to the level of nonsmokers after long-term cessation.