The liver is the largest internal organ in the body and is situated in the upper abdomen, on the right side of the body. It has many functions, including the production of bile, which is passed into the intestines, via a tube known as the bile duct. The liver filters toxins from the body. It is an essential organ in the conversion of food into energy and body tissue.
What is liver cancer?
Liver cancer can either start within the liver itself (a primary cancer) or start elsewhere in the body and then spread to the liver (a secondary cancer or metastatic). The majority of cancers seen in the liver are of a secondary type. Generally, cancers within the liver can be very difficult to cure. However, clinicians and scientists are finding more ways in which both primary and secondary cancers may be treated. In 2013, more than 23,000 men and 8,000 women in the United States will be diagnosed with primary liver cancer, most of them being >64 years old.
What is primary liver cancer?
The liver is a complex organ consisting of very many different types of cells. However, only the two principal cell types tend to form cancers. The cells, which perform the fundamental tasks of the liver, are called hepatocytes; the cancers these form are called hepatomas. The cells lining the bile ducts of the liver can also change into cancers; these are termed cholangiocarcinomas. Hepatomas almost always occur in the livers of people who have conditions that have damaged the liver over a long period of time. This damage causes scarring of the liver, known as cirrhosis. Any disease that causes cirrhosis of the liver can lead to a hepatoma. Fortunately, only a small number of people with cirrhosis actually get a hepatoma. Certain causes of cirrhosis have a higher chance of developing hepatomas. These are the viral infections hepatitis B and hepatitis C, the cirrhosis linked to excessive alcohol, and the cirrhosis of hemochromatosis (a condition wherein an excessive amount of iron is stored in liver cells). Currently we do not understand why cholangiocarcinomas develop. So, in most people there is no obvious reason why the cancer should form. It does occur more frequently in people who suffer a rare condition called sclerosing cholangitis, which causes slow and progressive damage to the bile ducts.
What is secondary liver cancer?
Nearly any cancer in the body can spread to the liver. Cancers more likely to have secondary growths in the liver are those from the stomach, pancreas and large bowel (colon). This is because the blood stream away from these digestive organs flows directly to the liver. Hence, all cancer cells that break away from the original growth are carried to the liver where they can embed and grow. Breast and lung cancers are relatively common cancers that can also form secondary growths within the liver.