About Pancreatic Cancer

What is Pancreatic Cancer?

The pancreas is an organ found in the abdomen, behind the stomach and surrounded by the small intestine, liver, and spleen, that produces enzymes and hormones. 

Most of the pancreas consists of the exocrine gland. This gland produces enzymes that aid in the breakdown of proteins and fats in foods. A small portion of the pancreas consists of endocrine cells. These cells produce insulin, a hormone that helps balance sugar levels in the blood.

At times these cells begin to grow abnormally and turn into tumors. Both the exocrine and endocrine cells can form tumors. While some tumors are not cancerous (benign), most tumors tend to be cancerous. These tumors often disrupt the normal activity of the cells and can also produce enzymes and hormones that can may spread and harm other organs and body functions.

While it is a serious disease, pancreatic cancer is rare. The American Cancer Society estimates that nearly 40,000 people in the United States (less than one-tenth of a percent of the population) will be diagnosed with a form of pancreatic cancer.

Pancreatic cancers are very difficult to detect and are often found in advanced forms. Very little is known about the cause of pancreatic cancer, but it tends to be more prevalent in smokers. The majority of cases are found in people over the age of 60.

Most pancreatic cancers do not produce symptoms until the cancer has spread to other parts of the body, therefore is not found until the cancer has spread, making treatment difficult. Most pancreatic cancers (tumors) grow large enough to cause extreme discomfort.

Types of Pancreatic Cancer
While both portions of the pancreas can form cancer, the majority of cases are found in the exocrine cells. It is important to know in which portion of the pancreas the tumor has formed. There are different treatment strategies and prognoses for each type. Treatment strategies are more often determined by the stage, or how developed the cancer is than by where the cancer is found.

Most pancreatic cancers begin in the ducts that carry pancreatic juices to the common bile duct, which empties into the duodenum, the first section of the small intestine. These cancers are called nonendocrine cancers and account for 98 percent of all pancreatic cancers. The most common of these types of cancer is adenocarcinoma. Nearly 95 percent of all pancreatic cancers are adenocarcinomas.

Tumors found in the endocrine cells are known as islet cell tumors. These tumors are very rare (accounting for only 2 percent of all cases) and are often benign.

There are approximately 20 types of pancreatic tumors. The nonendocrine pancreatic cancers include the following:

• Acinar cell carcinomas, which may produce excess amounts of the digestive enzymes normally produced by the pancreas;
• Adenosquamous carcinomas, which are similar to adenocarcinomas because they form in glands;
• Giant cell tumors, which have unusually large "giant" cells;
• Mucinous cystadenocarcinomas, which have spaces within a spongy tumor filled with a thick fluid called mucin;
• Pancreaticoblastoma, which is usually seen in children when it occurs;
• Papillary epithelial neoplasms, which occurs mostly in young women in their teens and twenties.

Endocrine cancers include:

• Gastrinoma, which makes large amounts of a hormone called gastrin;
• Insulinoma, which makes too much of the hormone insulin and causes the body to store sugar instead of burning sugar for energy.

August 2007