Introduction to Pancreatic & Biliary Tract Cancers
The pancreas is an organ of the endocrine and digestive systems. The endocrine portion contains islet cells that produce the hormones insulin and glucagon, which regulate the amount of sugar in the blood. The exocrine portion of the pancreas makes and secretes enzymes into the duodenum that help digest protein, starches, and fat.
About 30,000 new cases of pancreatic cancer are diagnosed in the United States each year. Because the early symptoms are vague, and there are no screening tests to detect it, early diagnosis is difficult. At the time of diagnosis, only about 10 percent of cancers can be removed. If the cancer has spread to local vital structures and blood vessels, the tumor is usually not removed.
The liver is one of the largest organs of the body and serves the vital function of filtering all the circulating blood. Cancer cells adrift in the bloodstream are likely to end up in one of the liver's thousands of blood-straining lobules, making this organ one of the most frequent sites of metastatic cancer.
Cancer that originates in the liver is called a hepatoma and is primary liver cancer. Hepatoma is a cancer of the hepatocytes—the main functioning liver cell. Hepatoma usually grows in the liver as a ball-like tumor, invading the normal tissue surrounding it.
Primary liver cancer is rare in the United States, accounting for less than 2 percent of all cancers; but it occurs much more frequently in some parts of Asia.
Primary cancer of the liver most often occurs in a person whose liver is damaged and "cirrhotic" because of chronic infection, particularly chronic hepatitis B and hepatitis C infections; alcoholism; or, rarely, exposure to cancer-producing substances.
Gallbladder and Bile Duct Cancers
Gallbladder and bile duct cancers are rare, and together make up only 2 to 3 percent of all cancers. Gallbladder cancers account for two-thirds of these cancers; bile duct cancers are responsible for the rest. An early diagnosis, which is rare, is usually made when the organ is removed because of gallstones.
The causes of gallbladder cancer remain unknown, although 70 to 90 percent of those with the disease have a history of gallstones. Either the gallstones themselves or the irritation, infection, or metabolic changes they cause may be a major factor.
The cause of bile duct cancer is unknown, but exposure to environmental or industrial toxins and infection by certain parasites have been associated with the disease.