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 Introduction
The liver is one of the major organs in the body responsible for removing toxins from the human body. It breaks down these toxins into pigmented substances and excretes these substances into our intestines. That is why when viruses, drugs or alcohol damage the liver, there is build-up of these pigmented substances. The result is jaundice, or yellowing of the whites of our eyes.
Medications are also broken down and excreted by the liver.
The liver is also the body's factory, manufacturing proteins, factors that allow our blood to clot normally and proteins that make up our muscles. Sugars and starches that the body requires to sustain life are made and stored by the liver.
It is the cells of the liver that become cancerous. Another term for liver cancer is hepatoma.
In Asia, the average age of a patient with liver cancer is about 40 to 50 years.
How common is Liver Cancer?
Liver cancer is common in Asian countries such as Hong Kong, Taiwan and Singapore. It is not as common in mainly Caucasian countries such as North America and Western Europe. Liver cancer is more common in males.
Causes and Risks
The association of viral infection of the liver and liver cancer has been known for more than 20 years. Hepatitis B carriers run a much higher risk of developing liver cancer than non-carriers. The hepatitis B virus is transmitted either during pregnancy from a mother who is a carrier to her unborn infant or during childhood from children who have been infected by their mothers.
The other major cause of liver cancer is alcohol-related damage to the liver. In Western countries, 80 to 90% of liver cancers are related to alcohol usage.
Aflatoxins, toxins which come from a mould which grows on grain and cereals in hot humid conditions, especially when stored in wet areas, is also a known liver cancer causing agent.
Symptoms
Abdominal pain, loss of weight and loss of appetite are the most common symptoms of liver cancer. They also indicate infection of the liver by viruses, such as hepatitis A or B. Up to 30% of patients have no symptoms.
Diagnosis
A blood test for alpha-fetoprotein or AFP may show elevated levels in up to 80% of patients with liver cancer. However, the AFP may also be elevated in pregnancy or other cancers.
Ultrasonography or CT (computerised tomography) scans of the liver are important to help in diagnosis. Once the diagnosis is made, angiography may be required to see if surgery is possible. During angiography, a x-ray dye is injected into the blood vessel in the groin of the patient. Numerous x-rays are then taken of the liver. The dye travels into the liver and outlines the extent of the cancer that can be seen on the x-rays. The procedure may be complicated by abdominal pain and the leakage of the dye and blood at the puncture site in the groin.
Clinical examinations, x-rays and pathology reports all help the medical team decide what the progress of an individual case of liver cancer may be. Then, the appropriate course of treatment will be put into action. The treatment strategy will vary from person to person. With prompt and appropriate treatment, the outlook for a person with liver cancer is reasonable. The extent of liver cancer, the presence of prior liver damage from hepatitis B or alcohol abuse, and the operability of the cancer determines the survival of a patient with liver cancer. If curative surgery is possible, the chance of surviving 5 years can be as high as 46%.
Treatment
Surgery depends on the size and location of the liver cancer, and the condition of the remaining portion of the liver. Since liver cancer normally arises from prior hepatitis B infection and alcohol-related liver damage, sometimes surgery is not possible even if the cancer is small and surgically removable. This is because removal of the part of the liver bearing the cancer leaves too little functioning liver to maintain life.
Where possible, surgery is recommended.
Chemotherapy and radiotherapy have small roles to play in the cure of liver cancer. Radiotherapy is hampered by the inability of normal liver tissue to tolerate sufficiently high doses of radiation. Chemotherapy drugs result in shrinkage of the cancer in up to 30% of patients and have side effects.
Blood supply for a healthy liver is brought in by the portal vein, while the cancer in the liver is supplied by the hepatic artery. Therefore a strategy of treating cancer in the liver by blocking the hepatic artery, hence decreasing its blood supply, has been used with some success. This is achieved by tying the hepatic artery during surgery or threading a thin tube up the blood vessels in the groin of the patient and injecting a gelling agent into the hepatic artery. Sometimes chemotherapy drugs are added to the gelling agent.
Frequently Asked Questions
I have relatives with liver cancer. Am I at higher risk of developing the disease?
Hepatitis B carriers who have relatives with liver cancer have a higher risk of developing liver cancer themselves. They should be evaluated and seen regularly by physicians who have a special interest in diseases of the liver.
I had hepatitis after travelling overseas. Will I develop liver damage?
There are many hepatitis viruses, such as hepatitis A virus, which is spread by eating contaminated food. This virus causes short-term liver damage after which the liver will repair itself and no further damage is done. There are also many viruses that do not specifically attack the liver but can cause mild, short-term generalised infection of the body including the liver, such as the dengue virus.
My father had colon cancer. Now he has liver cancer. Why does he have two cancers?
It may be wise to ask your father's physician again what he or she has found in your father. When a patient has colon cancer and this colon cancer later spreads to the liver, the patient is still suffering from colon cancer and not from liver cancer. The cancer cells that are in the liver will behave like colon cancer cells. It is not a new cancer but rather an advanced stage of colon cancer.
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