What is liver cancer?

Cells normally grow, divide and replace old cells as they die. This is a highly regulated process with strict control mechanisms. Sometimes this process goes wrong and new cells are produced that the body doesn't require. These form a tumour that can either be benign or malignant.

Benign tumours aren't cancer. They don't spread to other parts of the body and tend not to recur when surgically removed. Although considered less dangerous than malignant tumours, they can have serious effects due to their location or the pressure they exert.

Malignant tumours are cancer. Cancer cells can invade and damage adjacent tissues and are potentially life-threatening. They can spread to other parts of the body by direct extension, via the bloodstream or via the lymphatic system.

Cancer that begins in the liver cells is known as primary liver cancer. Most begin in the hepatocytes (liver cells) and are known as a hepatocellular carcinoma (HCC) or a malignant hepatoma. HCC accounts for 80 percent of primary liver cancers and is the fifth most common malignancy worldwide and the third most common cause of cancer-related death.

The liver is a common site of spread for cancers from other parts of the body, such as the colon, lungs and breast. These are secondary cancers called metastases. They’re not liver cancer per se and will not be addressed in this article.