Liver cancer is cancer that starts in the cells of your liver. Your liver is a football-sized organ that sits in the upper right portion of your abdomen, beneath your diaphragm and above your stomach.
A couple of different types of cancer can form inside of the liver. The most common type of liver cancer is hepatocellular carcinoma, which starts in the main type of liver cell (hepatocyte). Other types of liver cancer, such as intrahepatic cholangiocarcinoma and hepablastoma, are much less common.
Not all cancers that affect the liver are considered to be liver cancer. Cancer that starts in another area of the body — such as the colon, lung or breast — and then spreads to the liver is called metastatic cancer rather than liver cancer. And this kind of cancer is named after the organ in which it started — such as metastatic colon cancer to describe cancer that starts in the colon and spreads to the liver.
Cancer that spreads to the liver is more common than cancer that starts in the liver cells.