Hepatoma

A hepatoma (hepatocellular carcinoma) is a cancer that begins in the liver cells (a primary liver cancer).

Hepatomas are the most common type of cancer originating in the liver. In certain areas of Africa and Southeast Asia, hepatomas are even more common than metastatic liver cancer, and they are a prominent cause of death. These areas have a high prevalence of chronic infection with the hepatitis B virus, which increases the risk of hepatomas more than 100-fold. Chronic infection with hepatitis C also increases the risk of hepatomas. Finally, certain cancer-causing substances (carcinogens) produce hepatomas. In subtropical regions where hepatomas are common, food is often contaminated by carcinogens called aflatoxins, substances that are produced by certain types of fungi.

In North America, Europe, and other geographic areas where hepatomas are less common, most people with hepatomas are alcoholics with long-standing cirrhosis (severe scarring of the liver). Additional types of cirrhosis may lead to hepatomas, although the risk is lower with primary biliary cirrhosis than with other types.

Fibrolamellar carcinoma is a rare type of hepatoma that usually affects relatively young adults. It is not caused by preexisting cirrhosis, hepatitis B or C virus infection, or other known risk factors.

Symptoms

Usually, the first symptoms of a hepatoma are abdominal pain, weight loss, and a large mass that can be felt in the upper right abdomen. Alternatively, a person who has had cirrhosis for a long time may unexpectedly become much more ill. A fever may occur. Occasionally, the first symptoms are sudden abdominal pain and shock (extremely low blood pressure) caused by a rupture or bleeding of the tumor.

Diagnosis

In people with a hepatoma, levels of alpha-fetoprotein in the blood typically are high. Rarely, blood tests reveal low levels of blood sugar (glucose) or high levels of calcium, fats (lipids), or red blood cells.

At first, the symptoms do not provide many clues to the diagnosis. However, once the liver enlarges enough to be felt, a doctor may suspect a hepatoma, especially if the person has long-standing cirrhosis. Occasionally, a doctor can hear rushing sounds (hepatic bruits--due to the blood rushing through blood vessels inside the cancer) and scratchy sounds (friction rubs--due to irritation caused by the cancer rubbing against the liver surface and surrounding structures) when a stethoscope is placed over the liver.

Cancers that have not yet caused symptoms can sometimes be detected by abdominal ultrasound, computed tomography (CT) scans, or magnetic resonance imaging (MRI). In some countries where the hepatitis B virus is common, such as Japan, ultrasound scans are used to screen people with hepatitis B infection for liver cancer. X-rays taken after a radiopaque dye (a dye visible on x-rays) is injected into the main artery in the liver (hepatic artery) may reveal a hepatoma. This is particularly useful before surgical removal of the hepatoma because it shows the doctor the precise location of the liver's blood vessels.

A liver biopsy, in which a small sample of liver tissue is removed with a needle for examination under a microscope, can confirm the diagnosis (see Section 10, Chapter 134). The risk of bleeding or other injury during a liver biopsy generally is low.

Prognosis and Treatment

Usually, the survival rate for people in the United States with a hepatoma is poor because the tumor is detected at a late stage. In some other countries, such as Japan, the survival rate is higher because of routine screening and thus earlier detection. Occasionally, a person with a small tumor may do very well after the tumor is surgically removed. Chemotherapy drugs can be injected into a vein or into the hepatic artery, which then delivers a high concentration of the drugs directly to the cancer cells in the liver. Although chemotherapy drugs can temporarily slow the growth of the tumor, they do not cure the cancer.