Usually, when people speak of liver cancer, they mean a cancer that has begun somewhere else in the body and then spread to the liver. This is called secondary or metastatic disease or liver metastases. Due to its very high blood flow, as well as other factors still poorly understood, the liver is one of the most common places for metastases to take root. Tumors that originally arise in the colon, pancreas, stomach, lung, breast, or elsewhere can spread through the bloodstream to the liver, and then presenting as liver metastases. These metastases sometimes cause pain or damage liver function. In the Western Hemisphere, most cases of "liver cancer" actually are secondary, or metastatic cancers that started in another organ.Sometimes, cancer may arise in the cells of the liver itself. Cancer of the hepatocytes (the main functioning liver cell) is a primary liver cancer called hepatocellular carcinoma or hepatoma. Hepatoma usually grows in the liver as one or more round tumors, invading and destroying the normal tissue as it expands. Such primary liver cancer can also spread to other parts of the body including the lungs and lymph nodes. Within the liver, cancer can also arise from the tubes that carry the bile. These bile duct cancers called intrahepatic cholangiocarcinoma are less common than hepatoma and hard to detect. Today's discussion will focus on hepatocellular carcinoma or hepatoma.