The term liver cancer encompasses two major types of cancers found on or inside the liver; the primary liver cancer or hepatocellular carcinoma (HCC) which is the more serious condition and the secondary liver cancer or metastatic liver cancer which is the more frequently occurring.
Primary Liver Cancer
The liver is one of the most complex organs of the human body and its functions include: processing most of the nutrients absorbed from the intestines; controlling the amount of glucose (sugar), protein and fat is delivered into the bloodstream; producing blood-clotting agents and certain proteins; and detoxifying the bloodstream from harmful substances. Thus, the liver is composed of a variety of different cells such as those of its bile ducts, blood vessels, fat-storing cells and so on. Hepatocytes or the liver cells account for 80 percent of the liver tissue. For that reason, the majority (approximately 95 percent) of all cancers which originate on or within the liver (also known as primary liver cancer or hepatoma) affect hepatocytes and are called hepatocellular cancer or hepatocellular carcinoma (HCC). Other, less frequently occurring types of primary liver cancers are: cholangiocarcinoma (a.k.a. duct cancer) which begins in the bile ducts; hepatoblastoma is a rare primary liver cancer occurring in children under the aged of four and angiosarcoma or hemangiosarcoma which begins in the blood vessels of the liver and it is quite uncommon.
The beginning stages of primary liver cancer are usually asymptomatic and, therefore, the cancer is rarely discovered early enough to respond well to treatments and the prognosis is usually grim. By the time symptoms become apparent they may include the following:
- Loss of appetite and thus also loss of weight
- Abdominal pain which is most severe in the upper right part of the abdomen
- Back and shoulder pain
- Nausea and vomiting
- Overall weakness and fatigue
- An enlarged or swollen liver
- A swollen abdomen (ascites)
- Yellowing of the skin and the whites of the eyes (jaundice)
Although primary liver cancer can affect anyone, regardless of age, gender or race, some are more susceptible than others:
- More men seen to develop primary liver cancer than women.
- In the United States and Europe, most people who are diagnosed with primary liver cancer are over sixty years old while in Asia and Africa they tend to be between twenty and fifty years old.
- The hepatitis B virus (HBV) and the hepatitis C virus (HCV) are the most crucial risk factors for primary liver cancer.
- Cirrhosis develops scar tissue in the liver and increases the chances for primary liver cancer.
- Diabetics have increased chances of developing primary liver cancer.
- Ingesting foods contaminated with aflatoxins raises the likelihood for developing primary liver disease.
- Excessive consumption of alcohol and direct or secondary exposure to tobacco smoke increases the risk of primary liver cancer.
- Sclerosing cholangitis (bile duct disease) leads to scarring of the liver which in turn increases the risk of primary liver cancer.
Secondary Liver Cancer
Quite often, liver cancer originates in other parts of the body such as the colon, the stomach, the appendix, the pancreas, the breast, the lungs, the ovaries, and the prostate and so on and spreads into the liver through the circulatory or the lymphatic systems. Liver cancer that did not originate on or within the liver but reached it somehow is called metastatic liver cancer or secondary liver cancer.
By the time cancerous cells reach the liver from other organs, they would have most likely been discovered and treated in accordance to its origins.