About Liver Cancer
The liver is the largest organ inside the body, located on the right side of the abdomen under the rib cage. It performs many important functions, such as storing and breaking down nutrients they can be used by the body, and filtering and storing blood. A person cannot survive without his or her liver.
As the statistics indicate, liver cancer is more common among men than women. But, overall, the cancer is relatively rare in North America and Europe. By contrast, in certain African and East Asian countries, it is the most common of all types of cancer. For reasons as yet unknown, it is becoming even more common in these countries and less common in the U.S. and Europe.
What are the different types of liver cancer?
There are many kinds of tumors than can originate in the liver. Of the four main types that are cancerous (angiosarcomas, cholangiocarcinomas, hepatoblastomas, and hepatocellular carcinomas), hepatocellular carcinoma (also called hepatoma or HCC), is by far the most common, accounting for about 84 percent of all liver cancer cases. HCC starts growing in the hepatocytes, the main type of cell found in the liver.
What are the risk factors for liver cancer?
A risk factor is anything that increases a person’s chance of getting a disease. There are several known risk factors for liver cancer:
- Certain types of viral hepatitis, including chronic infection with hepatitis B virus (HBV) and hepatitis C virus (HCV), are associated with increased liver cancer risk. Scientists estimate that about 10–20 percent of people infected with HBV will develop liver cancer. The precise relationship between HCV and liver cancer incidence is still under study.
- Long-term exposure to aflatoxins – a group of carcinogenic chemicals produced by a fungus found in tropical and subtropical regions that often contaminates peanuts, wheat, soy beans, corn and rice – can raise the risk of liver cancer.
- Long-term use of anabolic steroids (male hormones) can slightly increase the risk of liver cancer. Anabolic steroids are used for treating men with abnormally low testosterone levels and for treating men and women with certain types of severe anemia (low red blood cell counts). These hormones are also sometimes abused by athletes trying to build their strength.
- In some parts of the world, contamination of drinking water with arsenic is a liver cancer risk factor.
- Long-term exposure to the industrial chemicals vinyl chloride and thorium dioxide, which are now either strictly regulated or banned from use, has been tied to liver cancer.
- Some studies suggest that tobacco use may be a liver cancer risk factor.
- Birth control pills (oral contraceptives) have been shown to raise the risk of liver cancer, but the studies suggesting this link involved versions of oral contraceptives that are no longer used. These older formulations of “the Pill” contained different types of estrogens and progesterones at far higher doses than current formulations. It is not known whether or not today’s oral contraceptives are associated with liver cancer.
- A history of other liver diseases, particularly cirrhosis of the liver, has been shown to raise the risk of liver cancer. Cirrhosis is a progressive disorder that causes formation of scar tissue in the liver, interfering with blood flow to the organ and with the ability of the liver to work properly. About 5–10 percent of people with cirrhosis of the liver develop liver cancer. Research also suggests that alcohol abuse and malnutrition can lead to both cirrhosis and liver cancer.
Can anything be done to prevent liver cancer?
Preventing infection with hepatitis B and C will reduce the risk of liver cancer. Strategies for lowering the likelihood of contracting hepatitis include following safe sex practices, not sharing needles, and getting vaccinated against hepatitis B. (All children should be vaccinated to prevent infection with hepatitis B.)
To reduce the risk of cirrhosis of the liver, a known risk factor for liver cancer, avoid excessive alcohol consumption.
What are the signs and symptoms of liver cancer?
Unfortunately, the signs and symptoms of liver cancer do not become apparent until the disease has progressed to a late stage.What’s more, many of the symptoms are nonspecific, meaning they can be vague and caused by many conditions. If you experience any of the following symptoms, however, see a doctor as soon as possible:
- unexplained weight loss;
- persistent lack of appetite;
- persistent abdominal pain;
- persistent feeling of being very full after only a small meal;
- swelling of the abdominal area with or without breathing difficulties;
- sudden jaundice (yellow-green coloration of the skin and eyes);
- a sudden change in your condition if you have chronic hepatitis or cirrhosis;
- liver enlargement or a mass that can be felt in the liver area.
What tests are used to diagnose liver cancer?
If liver cancer is suspected, the doctor will use several methods to diagnose the disease. First, the doctor will conduct a complete medical interview to look for risk factors and symptoms. Then he or she will perform a physical exam.
The doctor will also order certain diagnostic tests, most of them imaging tests to produce pictures of the liver and the surrounding organs. These tests may include: ultrasonography (ultrasound), which uses sound waves to generate images of the targeted area; computed tomography (CT scan), which is a specialized x-ray procedure in which x-rays are put together by a computer to create detailed cross-sectional images of the body; and magnetic resonance imaging (MRI), in which images are produced using a magnetic field. In addition, angiography – an x-ray procedure for examining blood vessels – may be done to allow the doctor to examine the arteries that supply blood to a tumor.
A laparoscopy is a method used to examine the liver directly through a thin, lighted tube inserted through a small incision in the front of the abdomen. The laparoscopy affords the doctor a clear view of the liver and surrounding organs, which can help the doctor plan for surgery or other treatments. It is also an opportunity for the doctor to remove a small sample of tissue, called a biopsy, for examination under a microscope. A biopsy is the only way to know for sure whether cancer is present.
In addition, the doctor may order an alpha-fetoprotein (AFP) blood test, which is a tumor marker study. Tumor markers are substances that are found at elevated levels in the blood of people with certain cancers. AFP levels are routinely checked in patients with suspected liver cancer.
Liver function tests – blood tests that take a detailed look at certain aspects of liver function – are also often ordered if cancer is suspected, particularly in people with known chronic liver disease. Abnormal results (such as alkaline phosphatase) can be a sign of cancer.
Once liver cancer is diagnosed, more tests will be performed to determine the extent of the disease (for example, chest x-rays and bone scans). This is called staging. The stage of a cancer is the most significant factor when devising a treatment plan.
What are the stages of liver cancer?
For liver cancer, the system used to stage the disease is the TNM system (also known as the American Joint Committee on Cancer, or AJCC, system). This system is based on three main variables. The “T,” which stands for tumor, is followed by a number ranging from 1 to 4, and this indicates the extent to which the tumor has spread within the liver and to nearby organs. The “N,” which is followed by a 0 or 1, indicates whether the cancer has spread to regional (nearby) lymph nodes – small collections of immune system cells that help fight infections – and how large those lymph nodes are. And the “M,” followed by a 0 or 1, tells whether the cancer has spread to distant organs in the body or to lymph nodes not located near the liver.
The TNM system is used to categorize the cancer in stages I through IV. The higher the stage number, the more the cancer has spread. Some doctors also divide the stages into letters (for example, IA or IB) to further clarify the extent of the cancer.
How is liver cancer treated?
Treatment of liver cancer depends on the type of tumor and the stage ofthe disease, the condition of the liver, and the patient’s age and overall health. The three main treatment methods include surgery, chemotherapy, and radiation therapy. Frequently, a combination of treatments is recommended.
Surgery to remove a tumor, called surgical resection, is the only way to cure liver cancer. Unfortunately, in the majority of liver cancers, complete removal of the cancer is not possible, either because the cancer has already spread beyond the liver or because the tumor is too large, or several tumors are present in different parts of the liver. Moreover, about 30 percent of hepatocellular carcinoma (HCC) patients in the U.S. have cirrhosis. This makes removal of even a small amount of liver tissue at the perimeter of the cancer prohibitive, as it would not leave enough liver tissue to perform the essential functions of the organ.
There are two other surgical methods for destroying liver tumors without removing them. The first is called cryosurgery, in which the tumor is destroyed by freezing it with a metal probe. The second is called ethanol ablation, which involves injecting alcohol directly into the tumor to destroy the cancer cells.
Chemotherapy, the use of cancer-killing drugs, is also used to treat liver cancer. Chemotherapy can be administered systemically by injection into a vein (IV) or by mouth. In systemic chemotherapy, the anticancer drugs enter the bloodstream and travel throughout the whole body, attacking cancer cells found beyond the liver. A combination of anticancer drugs is usually used, typically given in cycles (a period of treatment followed by a period of recovery, then another treatment period, etc.).
Systemic chemotherapy often does not work well for liver cancer. Another method, called hepatic artery infusion (a type of regional chemotherapy), may therefore be used. In this procedure, the anticancer drugs are injected directly into the artery that supplies the liver with blood. This allows high doses to reach the cancer. The procedure can be administered on an outpatient basis using a small pump placed just beneath the skin.
Radiation therapy, in which high-energy rays are used to kill cancer cells, is not often used for liver cancer, as studies do not demonstrate a strong effect on survival rates. However, researchers are investigating new techniques for administering radiation, as well as new combinations of radiation therapy and chemotherapy.
- Abdominal swelling
- Vague pain upper rightabdomen and back
- Weight loss
- Loss of appetite
- Occupational exposure to chemicals, e.g. vinyl chloride
- Alcohol abuse combined with heavy tobacco use
- Hepatitis B or C
- Poor nutrition
- Liver scans
- Blood tests
- Radiation therapy
- Clinical trials
- Hepatitis B & C vaccination
- Maximize protection against toxic chemicals
- Reduce alcohol consumption
- Don’t smoke