What Is Liver Cancer

The cells in the liver are meant to divide to replace those that die of injury or old age. Like all cell division in the body, this process is tightly controlled to proceed in an orderly manner, and controlled by the genes within each cell. Liver cancer starts within a single cell. Something changes the control mechanisms within this cell, and it starts dividing in a disorganized, uncontrolled manner. The abnormal cell makes millions of copies of itself, called clones. They fail to perform the normal functions of liver cells, but are only intent on dividing to make more copies of themselves. Eventually these abnormal cells form a clump, ortumor. A tumor is merely a swelling, and isn't necessarily cancerous. A benign tumor just grows in its local area, and although it may become very large it doesn't spread and isn't cancer. By contrast, a malignant tumor is cancer and has a capacity to spread to any area of the body. This process of spread is called metastasis . It is this capacity to spread to other vital organs that makes cancer so dangerous.

How Common is Liver Cancer?

Liver cancer is fairly uncommon in the U.S.A. with20,000 new cases and 15,000 deaths each year in the United States. It represents about 2% of all new cancers. About 3000 of the cases are in the liver itself, the remainder are in the Gall Bladder and bile drainage ducts. However, in Asia and Africa liver cancers are one of the most common cancers. Males are effected slightly more commonly than females, and the average patient is 50 years old. By contrast, benign liver tumors are more common in females and tend to occur at a younger age. Overall the death rate from liver cancer has dropped in the U.S.A. over the past 50 years. This is both from a decline in the number of cases, and better treatment for the disease.

 Liver Cancer Causes.

As for any cancer, the exact reason why any one person gets liver cancer and another doesn't remains unknown . However, several things have been noted which increase the risk, called isk factors:

1 Chronic Hepatitis can lead to changes in the liver cells associated with the most common type of liver cancer, hepatocellular carcinoma (HCC)

a)Hepatitis B --evidence of prior infection is found in 75% of liver cancer patients worldwide. It can lead to cirrhosis, below. The more common Hepatitis A (spread by feces) isn't associated with liver cancer.

b)Carcinogens (chemicals inducing cancer) such as aflatoxin food contamination (used by Iraq on the Kurds) and nitrosamines.

2. Cirrhosis of the liver (the liver can shrink up and become fibrous and fatty in response to chronic irritation). Causes of cirrhosis include:

a) Alcoholism-- alcoholic cirrhosis leads to 5% of liver cancer.

b)Hemochromatosis is an overload of iron in the liver. 20% of patients who get cirrhosis from the overload may develop HCC.

c)Alpha1- antitrypsin deficiency is a rare condition where a necessary enzyme is lacking to break down waste products in the liver and lung. HCC can develop in 40% of patients who get this type of cirrhosis.

3. Miscellaneous irritants to the liver including:

a) Polyvinyl Chloride (PVC) is linked to angiosarcoma.

b)Liver flukes are linked with bile duct cancer in China.

c) Thorotrast is a contrast dye for radiology studies no longer used after being linked to angiosarcoma.

d)Radiation Exposure can lead to liver sarcomas, sometimes as long as 5 decades after the exposure.
The common thread to liver cancer risk factors is chronic irritation, which causes the liver cells to divide more quickly than they ordinarily would to repair perceived damage. The more often cells divide, the more the chance for a genetically abnormal one to arise, with the gene changes leading to its becoming cancerous.