In 2014, it's estimated over 46,000 people in the U.S. will be diagnosed with pancreatic cancer. About one in 76 people in the U.S. will develop the disease. Pancreatic cancer affects equal numbers of men and women, almost always after the age of 45.
Cancer of the pancreas barely makes the top 10 most common cancers in the U.S. However, pancreatic cancer's tendency to spread silently before diagnosis makes it the fourth deadliest cancer diagnosis with more than 39,000 people expected to die of the disease in 2014.
Pancreatic cancer is classified according to which part of the pancreas is affected: the part that makes digestive substances (exocrine) or the part that makes insulin and other hormones (endocrine).
Exocrine Pancreatic Cancer
Although there are several different types of exocrine pancreatic cancer, 95% of cases are due to pancreatic adenocarcinoma.
Other less common exocrine pancreatic cancers include:
Squamous cell carcinoma
Giant cell carcinoma
Acinar cell carcinoma
Small cell carcinoma
The exocrine pancreas makes up 95% of the pancreas, so it's not surprising that most pancreatic cancers arise here.
Endocrine Pancreatic Cancer
Other cells of the pancreas make hormones that are released directly into the bloodstream (endocrine system). Cancerous tumors arising from these cells are called pancreatic neuroendocrine tumors or islet cell tumors.
Endocrine pancreatic cancers are uncommon, and are named according to the type of hormone produced:
Insulinomas (from an insulin-producing cell)
Glucagonomas (from a glucagon-producing cell)
Somatostatinomas (from a somatostatin-making cell)
Some pancreatic islet cell tumors do not secrete hormones and are known as non-secreting islet tumors of the pancreas.
Causes of Pancreatic Cancer
Pancreatic cancer occurs when cells in the pancreas grow, divide, and spread uncontrollably, forming a malignant tumor. The exact cause of pancreatic cancer is unknown.
Smoking is the major risk factor for pancreatic cancer. Cigarette smoking roughly doubles the risk for pancreatic cancer when compared to non-smokers. While diabetes is not a risk factor for pancreatic cancer, the two have been linked. Age, race, and family history are other risk factors for pancreatic cancer.