Hepatocellular Carcinoma

What is liver cancer (hepatocellular carcinoma, HCC)?

Liver cancer (hepatocellular carcinoma) is a cancer arising from the liver. It is also known as primary liver cancer or hepatoma. The liver is made up of different cell types (for example, bile ducts, blood vessels, and fat-storing cells). However, liver cells (hepatocytes) make up 80% of the liver tissue. Thus, the majority of primary liver cancers (over 90%-95%) arises from liver cells and is called hepatocellular cancer or carcinoma.

When patients or physicians speak of liver cancer, however, they are often referring to cancer that has spread to the liver, having originated in other organs (such as the colon, stomach, pancreas, breast, and lung). More specifically, this type of liver cancer is called metastatic liver disease (cancer) or secondary liver cancer. This is a much more common problem around the world than primary liver cancer and frequently leads toconfusion, because the term liver cancer actually can refer to either metastatic liver cancer or hepatocellular cancer. The subject of this article is hepatocellular carcinoma, which I will refer to as liver cancer.

What is the scope of the liver cancer problem?

Liver cancer is the third most common cancer in the world. A deadly cancer, liver cancer will kill almost all patients who have it within a year. In 2000, it was estimated that there were about 564,000 new cases of liver cancer worldwide, and a similar number of patients died as a result of this disease. About three-quarters of the cases of liver cancer are found in Southeast Asia (China, Hong Kong, Taiwan, Korea, and Japan). Liver cancer is also very common in sub-Saharan Africa (Mozambique and South Africa).

The frequency of liver cancer in Southeast Asia and sub-Saharan Africa is greater than 100 cases per 100,000 population. In contrast, the frequency of liver cancer in North America and Western Europe is much lower, less than five per 100,000 population. However, the frequency of liver cancer among native Alaskans is comparable to that seen in Southeast Asia. This reflects the prevalence of hepatitis B infection, which is the most common cause of this cancer worldwide. Recent data show, however, that the frequency of liver cancer in the U.S. overall is rising. This increase is due primarily to rising obesity and diabetes rates, and to chronic hepatitis C, another infection of the liver that causes liver cancer.