Liver cancer is the abnormal growth of cells in the liver resulting in a liver tumor. If the abnormal cells originated as liver cells, the resulting collection of cells is called a primary liver tumor. Some liver tumors are benign, meaning they are not cancerous and do not spread to other parts of the body. Malignant liver tumors, however, can invade other organs, and spread throughout the body. Most primary malignant liver cancers are classified as hepatocellular carcinoma or called hepatomas.
A much more common cancer of the liver is a metastatic liver tumor. In this case, cancerous cells from another part of the body are carried to the liver by the blood or other bodily fluids. Metastatic liver tumors can spread to the liver from the colon, lung, breast, stomach and pancreas, as well as other sites in the body.
More than 21,300 cases of primary liver cancer are expected to be diagnosed in the United States in 2008. Primary liver cancer is expected to result in approximately 18,410 deaths during that time.1 Five-year relative survival rates for metastatic cancer to the liver is 3.3 percent.1