Pancreatic Cancer

The pancreas is gland in the digestive system. The pancreas secretes digestive enzymes into the first part of the small intestine, called the duodenum, to aid in the digestion of protein, fats, and carbohydrates. The pancreas also produces insulin, which it secretes directly into the bloodstream.

The pancreas is made up of two types of cells:

  • Exocrine cells: These cells form the glands and ducts that produce and deliver pancreatic enzymes used in digestion. The majority of cells in the pancreas are exocrine cells.
  • Endocrine cells: These cells exist in small clusters called islets and produce hormones — including insulin and glucagon — that are released directly into the blood and help regulate blood sugar.

Both exocrine cells and endocrine cells each can form their own type of cancer.

Types of Pancreatic Cancer

Exocrine pancreatic cancers and endocrine pancreatic cancers have different risk factors and causes, symptoms, and are diagnosed differently.

Exocrine Pancreatic Cancer
Exocrine pancreatic cancers are the most common pancreatic cancers, and nearly all exocrine cancers are pancreatic adenocarcinomas. Pancreatic adenocarcinomas usually form in the ducts of the pancreas but also can develop from cells that produce pancreatic enzymes (acinar cell carcinomas). Less common exocrine cancers include adenosquamous carcinomas, squamous cell carcinomas, signet ring cell carcinomas, and undifferentiated carcinomas.

Endocrine Pancreatic Cancer
Tumors of the endocrine are less common. Often, they are called pancreatic neuroendocrine tumors (NETs) or islet cell tumors. Pancreatic NETs include:

Functioning NET(s): Functioning tumors are named for the type of hormone the tumor cells create. About half of pancreatic tumors are functioning NET(s); most are gastrinomas and insulinomas (often benign), but they also can include glucagonomas, somatostatinomas, VIPomas, and PPomas.

Ampullary cancer, which starts where the bile duct and pancreatic duct come together (the ampulla of Vater), is not a pancreatic cancer but often is treated the same way.