Liver cancers are malignant tumors that begin in various parts of the liver. The liver is the largest organ in the body and is found behind the ribs on the right side of the abdomen. The liver performs several vital functions to keep the body healthy. It processes and stores many of the nutrients absorbed from the intestine and secretes bile into the intestine to help the body digest fat from food. The liver also plays an important part in removing toxic substances from the blood.
Cancer that begins in the liver is called primary liver cancer. Although primary liver cancer is the fifth most common cancer around the world, it is much less common in the United States. However, it is common for cancer to spread to the liver from the colon, lungs, breasts, or other parts of the body. When this happens, the disease is not called liver cancer. The cancer in the liver is a secondary cancer. It is named for the organ or the tissue where it began, such as metastatic colon cancer which spread to the liver.
The types of liver cancers are named for the different types of cells where they begin. These cancers have different causes, are treated differently, and have a different outlook for recovery.
Most primary liver cancers begin in the main type of liver cells, called hepatocytes. This type of cancer is called hepatocellular carcinoma or malignant hepatoma. About 75 percent of primary liver cancers are of this type. In the United States, this type of cancer usually begins in many locations throughout the liver. It can also begin as a single tumor that grows larger and then spreads throughout the liver. Children can also have primary liver cancers. These include hepatocellular carcinoma or hepatoblastoma, a rare cancer that usually affects children younger than four. Treatment for children with liver cancer is different than treatment for adults.
About 10 percent to 20 percent of primary liver cancers arising from the ducts draining bile into the small intestine. Such tumors are called cholangiocarcinomas. These cancers start in the small bile ducts (tubes in the liver that carry bile to the gallbladder) or in the main common bile duct just beneath the liver. Cholangiocarcinomas are often treated the same way as hepatocellular carcinomas. A small number of liver cancers are angiosarcomas and hemangiosarcomas. These are rare cancers that begin in the blood vessels of the liver.
Liver cancer is sometimes called a silent disease because in early stages, it often does not cause symptoms. As the cancer grows, symptoms may include pain in the upper abdomen on the right side, possibly extending to the back and shoulder; swollen or bloated abdomen; weight loss; loss of appetite and feelings of fullness; weakness or tiredness; nausea and vomiting; yellow skin and eyes, and dark urine from jaundice; and fever.
Patients newly diagnosed with liver cancer are referred to specialists for treatment. Specialists who treat liver cancer include surgeons (especially those who specialize in liver surgery), gastroenterologists, medical oncologists, and radiation oncologists.