What Causes Pancreatic Cancer?

In recent years, scientists have learned a great deal about the changes that happen in the cells of the pancreas when cancer develops. They have learned, for example, that certain changes in the DNA (a chemical that carries the instructions for nearly everything our cells do) can make normal cells cancerous. Certain genetic diseases (including familial adenomatous polyposis, nonpolyposis colon cancer, and familial breast cancer associated with the BRCA2 gene) seem to play a role in the development of pancreatic cancer.

In about 90 percent of cases, however, mutations (changes) in the genes that control the growth and division of cells that are related to cancers of the exocrine pancreas occur after you are born and are not inherited from your parents. These mutations may happen because you have been exposed to cancer-causing chemicals (including those found in tobacco smoke) in the environment or your diet. Sometimes these changes occur for no apparent reason.

Risk Factors for Pancreatic Cancer

Doctors and researchers believe that certain factors, known as risk factors, increase a person’s chances of getting pancreatic cancer. However, not everyone with a risk factor will develop pancreatic cancer and people without any risk factors can develop the disease.

Risk factors for pancreatic cancer include:

• Age - The risk of getting pancreatic cancer increases with age. Most people who get pancreatic cancer are older than 50 and more than 70 percent are older than 65.
• Chronic pancreatitis - Chronic pancreatitis, a long-term inflammation of the pancreas, has been linked to increased risk of pancreatic cancer. This might be because patients with pancreatitis are more likely to also have other risk factors such as smoking.
• Diabetes - Pancreatic cancer occurs more often in people who have diabetes, especially type II diabetes, than in those who do not. The risk is highest within 5 years of the diagnosis of diabetes.
• Diet - People who eat a lot of red meat, pork, and, especially, processed meat (such as sausage and bacon) are more likely than others to get pancreatic cancer.
• Family history - The risk of pancreatic cancer triples if your mother, father, or sibling had the disease. You also have a higher risk of pancreatic cancer if your family has certain hereditary forms of melanoma or colon, breast, and ovarian cancer. An inherited tendency to develop pancreatic cancer may be a factor in as many as 10 percent of cases.
• Obesity - Very overweight people are 20 percent more likely to get pancreatic cancer.
• Occupational exposure - Heavy exposure to certain pesticides, dyes, and chemicals related to gasoline may increase the risk of developing pancreatic cancer.
• Race - African Americans are up to 50 percent more likely than whites to be diagnosed with pancreatic cancer, possibly because more African-American men smoke and have diabetes and more African-American women are overweight than their white counterparts.
• Smoking - Cigarette smokers are two or three times more likely than nonsmokers to develop pancreatic cancer. Scientists believe that cancer-causing chemicals in cigarette smoke enter the blood and damage the pancreas. About 30 percent of pancreatic cancer cases are believed to result directly from cigarette smoking.
• Stomach problems - Infection of the stomach with a bacterium called Helicobacter pylori (H. pylori) can increase the risk of pancreatic cancer. Also, some researchers believe that having too much stomach acid can increase the risk.

This content has been reviewed and approved by Myo Thant, MD.