What is liver cancer?
Liver cancer is a type of malignant tumor that begins
in the liver, the largest internal organ in the body. Most liver cancers develop
from the cells in the liver called hepatocytes. These cancers are referred to as
primary liver cancer. Rarely, they may develop from cells lining the bile duct
or the blood vessels. Other cancers spread to the liver from another area, such
as the colon, breast, or lung. These are referred to as metastatic cancers.
The liver is vital for several life functions,
including the digestion of food, the collection and filtering of blood from the
intestines, storing nutrients, metabolizing food into energy, helping the blood
produce clotting factors, removing toxic waste from the body, and helping
maintain the proper level of sugar in the body. A person cannot live without a liver.
Who gets liver cancer?
Anyone can get liver cancer, but some people are at
higher risk. Risk factors for liver cancer include:
- Infection with hepatitis B virus (HBV) or hepatitis C virus (HCV):
Infection with HBV or HCV is the main cause of liver cancer. It often
develops after many years of infection with either of these viruses.
- Aflatoxin: Liver cancer can be caused by aflatoxin, a harmful substance
made by certain types of mold. This toxic substance can form on nuts and
grains, including peanuts and corn. High levels of aflatoxin are rare in the
United States, however, due to safety regulations. They are more common in
parts of Asia and Africa.
- Iron storage disease: Liver cancer may occur in people who have a
disease that causes the body to store too much iron in organs, including the liver.
- Cirrhosis: Liver cancer is usually preceded by a condition called
cirrhosis, a disease in which scar tissue replaces damaged liver cells.
Cirrhosis can be the result of hepatitis B or C infection or heavy alcohol use.
- Heavy alcohol use: This is a risk factor because alcohol abuse is linked
to cirrhosis.
- Obesity and diabetes: Studies have shown that obesity and diabetes may
be risk factors for liver cancer.
What are the different types of liver cancer?
There are three main types of liver cancer. These are:
- Hepatocellular carcinoma (HCC): This is the most prevalent type of liver
cancer, accounting for close to 90 percent of cases. Almost 80 percent of
patients diagnosed with HCC will have underlying cirrhosis.
- Cholangiocarcinoma (bile duct cancer): This cancer grows in the bile
duct of the liver. This narrow tube extends from the liver to the small
intestine. It accounts for about 9 percent of liver cancers.
- Angiosarcoma: This rare kind of liver cancer accounts for only about one
percent of cases. It is an aggressive rapidly growing cancer that starts in
the blood vessels of the liver.