The human liver that is situated in the upper abdomen is the largest glandular organ of the body. Liver continuously filters blood that circulates through the body, converting nutrients and drugs absorbed from the digestive tract into ready-to-use chemicals.
It also performs may other important functions, such as removing toxins and other chemical waste products from the blood and readying them for excretion. Because all the blood in the body must pass through it, the liver is unusually accessible to cancer cells traveling in the bloodstream.
Cancer of the liver, which may be primary or secondary cancer, involves an uncontrolled growth of cells. Primary cancer arises within the liver and in its early stages exists only in the liver. Secondary liver cancer, also called metastatic cancer, originates in another organ, such as the colon, stomach, pancreas or breast and then spreads to the liver. Because secondary cancer is present in at least two organs, the treatment possibilities are more limited than for primary liver cancer.
Primary liver cancer can affect anyone, but it occurs most frequently in people with advanced liver disease. In the United States, the risk is greatest for those with longstanding hepatitis B, advanced hepatitis C and cirrhosis. Because hepatitis viruses are so widespread, liver cancer is the second most common cause of cancer death worldwide