An unusual type of hepatocellular carcinoma called fibrolamellar tends to occur in young women. Tumors that develop in the bile ducts are called cholangiocarcinomas ( see "Bile Duct" ).
Most commonly, cancer in the liver has spread there from another organ and is therefore a type of metastatic cancer ( see "Metastatic Cancer" ).
How It Spreads Liver cancers can spread to other areas through either the lymph system or the blood. Most often the cancer first moves into the lymph nodes in the region of the liver (porta hepatis), then goes to other lymph nodes or into the lung or bones. Tumor cells can also spread into the abdominal cavity, causing the accumulation of fluid (ascites) or masses elsewhere in the abdomen.
What Causes It Hepatocellular carcinoma most often develops in damaged livers. Long-standing infection with either the hepatitis B or hepatitis C virus often precedes it and is therefore seen as a significant risk factor.
Cirrhosis of the liver (from, for example, a viral infection, alcohol, toxin exposure or a genetic defect of metabolism) also increases the likelihood of hepatocellular carcinoma, presumably because of chronic inflammation in the liver. In fact, an estimated 5 percent of all people with cirrhosis of the liver will eventually develop liver cancer. Fifty to 80 percent of all people with liver cancer have cirrhosis.
Certain chemicals are associated with increased liver cancer, and a link has been established with a plant fungus (aflatoxin) that is ingested with the normal diet in a region in Africa. Oral steroid use may also increase the risk.
