Liver cancer is the growth of malignant cells in the liver, the largest internal organ in the body. Although primary liver cancer is one of the most common cancers worldwide, it is much less common in the United States. Liver cancer is often a complication of liver diseases such as hepatitis or cirrhosis.

The liver is a large, complex organ with a number of vital functions, including bile production and removing alcohol and toxins from the blood. The liver is a common site for cancer metastasis, which is cancer that has spread from its area of origin (e.g., breast cancer, lung cancer). There are several types of primary liver cancer, which originate in the liver and are much less common than metastatic, or secondary, liver cancer.

Liver cancers are seldom diagnosed early because they may have no symptoms. Possible indicators include weight loss, lack of appetite, jaundice and abdominal pain or swelling. A physician may use a number of diagnostic tests to confirm liver cancer, including ultrasound, blood tests, CAT scan, MRI and biopsy.

If the cancer is confined to one part of the liver and is detected early, it may be curable by surgery. Other possible treatments include radiation, chemotherapy and ablation, a procedure that involves the use of locally applied alcohol, radio waves or cold to destroy tumors. In some cases, a liver transplant may be necessary. Treatment for the disease varies depending on the type and severity of the cancer.

Less than 10 percent of Americans with liver cancer live five years or more after diagnosis, according to the American Cancer Society. This survival rate has doubled in recent decades, and researchers hope to increase it further through improved methods of diagnosis, treatment and prevention. Children rarely get liver cancers, and most who do develop a form of the disease that is highly curable.

There are several ways to help prevent liver cancer. These involve measures to control risk factors such hepatitis, alcoholism and exposure to certain chemicals.