Overview

Pancreatic cancer is a disease in which normal cells in the pancreas malfunction and begin to grow uncontrollably. These cancerous cells can build up and form a mass, called a tumor. As it grows, a pancreatic tumor can affect the functioning of the pancreas, grow outward to involve nearby blood vessels and organs, and eventually metastasize (spread) to other parts of the body.

Function of the pancreas

The pancreas is a pear-shaped gland located in the abdomen between the stomach and the spine. It is about six inches in length and is composed of two major components:

• The exocrine component, made up of ducts and acini (small sacs on the end of the ducts), produces enzymes (specialized proteins) that are released into the small intestine to help the body digest and break down food, particularly fats.
  
  
• The endocrine component of the pancreas is made up of specialized cells clustered together in islands within the organ, called islets of Langerhans. These cells produce specific hormones, with the most important one being insulin, a substance that helps control the amount of sugar in the blood.

Types of pancreatic cancer

It is important to determine if the cancer started in the exocrine or endocrine component of the pancreas, as the diagnosis and treatment of each type is much different. The most common type of pancreatic cancer is called ductal adenocarcinoma, or simply, adenocarcinoma. In this type, the cancer begins in the exocrine component. The remainder of this section focuses on adenocarcinoma.

Much less commonly, tumors begin in the islets of Langerhans, the endocrine component. These are known as islet cell tumors or pancreatic neuroendocrine tumors. There are several subtypes of pancreatic endocrine tumors. These neuroendocrine tumors may produce chemicals such as insulin; if this type of tumor grows without producing such hormones, it is called non-functioning. If the tumor produces a hormone(s), the hormone(s) may cause metabolic imbalances, such as a very low blood sugar level (such as the case with insulinomas) or a very high blood sugar level (such as with glucagonomas), or other problems like severe diarrhea (a symptom of VIPomas, which produce a substance called vasoactive intestinal peptide). It is important to distinguish a neuroendocrine tumor from an adenocarcinoma of the pancreas because each acts and is treated very differently from one another. For more information, read Cancer.Net’s Guide to Islet Cell Tumors.

Statistics

In 2009, an estimated 42,470 adults (21,050 men and 21,420 women) in the United States will be diagnosed with pancreatic cancer. It is estimated that 35,240 deaths (18,030 men and 17,210women) from this disease will occur this year. Pancreatic cancer is the tenth most common cancer in men and women, and the fourth leading cause of cancer death in men and women. As explained above, most pancreatic cancers are adenocarcinomas, and it is to that type of pancreatic cancer that the following statistics apply.

Because pancreatic cancer often does not cause specific symptoms early on in its development, it is often not detected until the cancer has metastasized beyond the pancreas to other areas of the body. The overall one-year relative survival rate (percentage of people who survive at least one year after the cancer is detected, excluding those who die from other diseases) of people with pancreatic cancer is 24%, and the five-year relative survival rate (percentage of people who survive at least five years after the cancer is detected, excluding those who die from other diseases) is approximately 5%. If the cancer is detected at an early stage where surgical resection (surgical removal of the tumor) is possible, the five-year relative survival rate is about 20%.

Cancer survival statistics should be interpreted with caution. These estimates are based on data from thousands of cases of this type of cancer in the United States each year, but the actual risk for a particular individual may differ. It is not possible to tell a person how long he or she will live with pancreatic cancer. Because the survival statistics are measured in one-year or five-year intervals, they may not represent advances made in the treatment or diagnosis of this cancer.

Statistics adapted from the American Cancer Society's publication, Cancer Facts & Figures 2009.

Find out more about basic cancer terms used in this section.