Pancreatic cancer is one of the most deadly of all cancers, but it is rare, accounting for only 2 percent of cancer cases according to the American Cancer Society (ACS). Pancreatic cancer is the fourth leading cause of cancer deaths.

Pancreatic cancer occurs when malignant cells form in the pancreas because of unrepaired damage to the cells’ DNA. The cancer grows rapidly with no symptoms in its early stages. Because of this lengthy silent period, the cancer is usually undetected until it has spread (metastasized) to other areas of the body. Pancreatic cancer can spread to the lymph nodes, intestines, liver, bile duct, bones and lungs.

The pancreas is a gland located in the midsection of the abdomen behind the stomach. It is has a wide end (head), a middle portion (body) and a narrow section (tail). About three-fourths of pancreatic cancers occur in the pancreatic head. The cells of the pancreas actually form two intermingled glands, which produce different chemicals:

• Exocrine pancreas. Most of the pancreatic cells are exocrine glands and ducts. They produce enzymes and transport them to the digestive tract to help digestion. Cancer can form in the cells, ducts or tissues of the exocrine pancreas. Most pancreatic cancers form in the exocrine cells.
  
  
• Endocrine pancreas. Endocrine cells form clusters called islets throughout the pancreas. These cells produce the hormones insulin and glucagon, which control blood sugar, and somatostatin, which suppresses the release of insulin and glucagon. A small percentage of pancreatic cancers are of this type.

The pancreas is surrounded by other structures and organs, making it difficult to detect abnormalities such as tumors. Pancreatic cancer rarely causes early symptoms. By the time symptoms are apparent, the disease has usually metastasized to neighboring tissues or distant organs. Such late diagnosis contributes to the high mortality rate.

The ACS estimates that 37,680 Americans will be diagnosed with pancreatic cancer in 2008. The risk increases with age. African Americans are 40 to 50 percent more likely than whites to develop pancreatic cancer. The one-year survival rate is 24 percent and the five-year survival rate is about 5 percent for exocrine pancreatic cancer. This rate improves to 20 percent in patients where the cancer is confined to the pancreas, although diagnosis this early is uncommon.