For an explanation of the pancreas, please see the description under "What is the pancreas?" in Pancreatic Diseases.
Cancer is an uncontrolled growth of abnormal cells that form tumours, damage normal tissue and that may eventually spread throughout the body (metastasise). Most pancreatic cancers (95%) are adenocarcinomas that develop in the pancreatic ducts and sometimes in the enzyme-producing cells of the exocrine tissue. Endocrine tumours are usually less aggressive than exocrine tumours and are rarer. They may be benign tumours that do not metastasise (such as an insulinoma) or malignant, including a group of cancers called islet cell cancers. Endocrine cancers are usually detected earlier than exocrine cancers because they often produce excessive amounts of the hormones insulin and glucagon that frequently result in the development of characteristic symptoms.
The remainder of this discussion focuses on exocrine cancer because it is more common and the tumours are more aggressive. Unfortunately, they are hard to detect at an early stage. Since the pancreas is deep in the body, tumours usually cannot be seen or felt during a physical examination and, by the time symptoms develop, the cancer has often spread throughout the pancreas and beyond. One exception to this is a cancer that forms at the ampulla, the point where the pancreatic and bile ducts empty into the duodenum. Ampullary cancer often obstructs the flow of bile from the bile duct and causes jaundice, so it has the potential to be detected earlier than most exocrine cancers.
According to Cancer Research UK, 8500 UK people were diagnosed with pancreatic cancer in 2010. It is the tenth commonest cause of cancer death in the UK, two thirds occurring in those over 70 years of age.