Liver Cancer
The liver is the largest internal organ in the body. It lies under the right ribs, just beneath the right lung and diaphragm (the membrane below the lungs that moves up and down as you breathe). If you were to poke your fingers up under your right ribs, you would almost be touching your liver.
The liver is shaped like a pyramid and is divided into right and left lobes. Unlike most other organs, the liver receives blood from 2 sources. The hepatic artery supplies the liver with blood that is rich in oxygen. The portal vein carries nutrient-rich blood from the intestines to the liver.
The liver performs several vital functions. It processes and stores many of the nutrients absorbed from the intestine. It also makes some of the clotting factors needed to stop bleeding from a cut or injury. And it secretes bile into the intestine to help absorb nutrients. The liver also plays an important part in removing toxic wastes from the body.
Because the liver is made up of several different types of cells, several types of tumors can form in the liver. Some of these are cancerous and some are benign (not cancerous). These tumors have different causes and are treated differently. The outlook for your health or recovery depends on what type of tumor you have.
Benign Tumors
Hemangioma (he-man-ge-O-muh) is the most common type of benign liver cancer. It starts in blood vessels. Because most of these tumors don’t cause symptoms, they do not need treatment, although some may bleed and need to be removed by surgery.
Hepatic adenomas (huh-pat-ic ad-uh-noh-muhs) are benign tumors that start from the main type of liver cells (hepatocytes). Again, most do not cause symptoms and do not need treatment. However, if they cause stomach pain, a mass in the abdomen, or blood loss, they may need to be removed. Women have a much higher chance of having one of these tumors if they take birth control pills, although this is rare. Stopping the pills can cause the tumor to shrink. Men who use anabolic steroids (“steroids”) may also develop these. They can also shrink when the drugs are stopped.
Focal nodular hyperplasia (hy-per-play-zuh), or FNH, is a tumor-like growth of several cell types. Although FNH tumors are benign, it can be hard to tell them apart from true liver cancer. If there are symptoms, the tumor can be removed.
Malignant Tumors
While there are other types of liver cancer, the most common form in adults is called hepatocellular carcinoma (huh-pat-uh-CELL-u-lar car-sin-o-muh).It begins in the hepatocytes, the main type of liver cell. About 3 out of 4 primary liver cancers are of this type. Most of the information in this article refers to hepatocellular cancer.
This type of cancer can have different growth patterns. Some begin as a single tumor that grows larger. Only late in the disease does it spread to other parts of the liver.
A second type of liver cancer begins in many spots throughout the liver and is not confined to a single tumor. This is most often seen in people with liver cirrhosis and is the most common pattern seen in the United States.
Doctors can identify several subtypes of hepatocellular cancer by looking at tissue under a microscope. The most important is called fibrolamellar. This subtype, which is rare, has a better outlook (prognosis) than other forms of liver cancer.
Cholangiocarcinomas account for 1 or 2 out of every 10 cases of liver cancer. These cancers start in the small bile ducts, tubes that carry bile to the gallbladder. Although the rest of the information here covers hepatocellular cancers, cholangiocarcinomas are often treated the same way. For more information on this type of cancer, please see the ACS document "Bile Duct Cancers."
Most of the time when cancer is found in the liver, it did not start there but spread to the liver from a cancer that began somewhere else in the body. These tumors are named after the place where they began (primary site) and are further described as metastatic For example, cancer that started in the lung and spread to the liver is called metastatic lung cancer with spread to the liver. The rest of the information given here covers only primary liver Cancer, that is, cancer that begins in the liver.
What Causes Liver Cancer?
A risk factor is anything that affects a person's chance of getting a disease. Different cancers have different risk factors. Some risk factors, such as smoking, can be controlled. Others, like a person's age or family history, can't be changed. But having a risk factor, or even several, does not mean that a person will develop cancer.
Scientists have found several risk factors that make a person more likely to get liver Cancer.
Gender: Men are more likely to get liver cancer than are women. This could be because of the behaviors listed below such as smoking and alcohol abuse.
Certain types of liver disease: On-going (chronic) infection with hepatitis B virus (HBV) and hepatitis C virus (HCV) is a very important liver Cancer risk. These infections, which are common in many parts of the world, make liver cancer the most common cancer in these areas. There are also some inherited liver diseases that increase the risk of liver cancer. People with hepatitis A infection do not have an increased risk of liver Cancer.
Cirrhosis(suh-row-sis): Cirrhosis is the result of scar tissue in the liver. This can often lead to cancer. In this country, the major causes of liver cirrhosis are alcohol abuse and hepatitis B and C. Another cause is a disease that results in too much iron in the liver.
Tobacco use: There is a link between smoking and liver cancer. The risk may be even greater for people who also abuse alcohol.
Diabetes: This disease can also increase the risk of liver cancer, usually in people who have other risk factors such as heavy drinking or viral hepatitis.
Obesity: Obesity might increase the risk of getting liver Cancer.
Aflatoxins: These cancer-causing substances are made by a fungus that can contaminate peanuts, wheat, soybeans, groundnuts, corn, and rice. Long-term exposure to aflatoxins can increase the risk of liver Cancer. In the United States and Europe, these foods are tested for aflatoxins.
Vinyl chloride and thorium dioxide (Thorotrast): These chemicals are risk factors for several types of liver cancer. They have become much less important since Thorotrast is no longer used and exposure to vinyl chloride is strictly controlled.
Anabolic steroids: These are male hormones that are used by some athletes to increase their strength. Long-term use of these can slightly increase the risk of liver Cancer.
Arsenic: In some parts of the world, drinking water contaminated with arsenic increases the risk of liver cancer.
Birth control pills: Birth control pills may slightly increase the risk of liver cancer. Most of the studies linking birth control pills and cancer involve types of pills that are no longer used. Birth control pills are now made differently and it is not known if they increase liver Cancer risk.
Symptoms of Liver Cancer
Most of the time liver cancer does not cause symptoms in the early stages. The symptoms below could be caused by liver cancer. But they can also be caused by other cancers or conditions. Still, if you have any of the following problems, see a doctor right away.
- Weight loss (for no known reason and without your trying to lose weight)
- On-going lack of appetite
- Feeling very full after a small meal
- Liver swelling or a mass that can be felt in the area of the liver
- Ongoing stomach pain
- Swelling in the area of the stomach
- Yellow-green color to the skin and eyes (jaundice)
- Becoming sicker if you have chronic hepatitis or cirrhosis
Treatment of liver cancer depends on the size of the tumor and whether there is cirrhosis. People without cirrhosis can do well if the tumor is removed or with treatments that destroy the tumor without surgery (such as injecting them with alcohol or heating them to high temperatures in a procedure called radiofrequency ablation). If there is cirrhosis, or a very large tumor, most experts recommend liver transplantation as the main treatment.
Surgery
At this time surgery, either to remove the tumor or to do a liver transplant, offers the only chance to cure liver cancer. If all of the cancer that the surgeon can see at the time of the operation can be removed, you have the best outlook for survival. Complete removal of most liver cancers is not possible. Often the cancer is large, is found in many different parts of the liver, or has spread beyond the liver. Also, many people with cirrhosis do not have enough healthy liver left to make surgery an option.
A liver transplant has become an option for people with small liver cancer. For now, this method is reserved for those with a few small tumors but whose cancer cannot be totally removed, either because of the location of the tumors or because not enough normal liver remains. Over 2500 transplants were performed in people with liver cancer in the last 2 years. The 5-year survival for these patients is around 70%. Not only is the risk of a second new liver cancer eliminated, but the new liver will function normally.
Not many livers are available for patients with cancer because they are most often used for more curable diseases. Patients often must wait a long time, often too long, for a liver to be found. For that reason, some doctors suggest a limited resection first and then a transplant if the cancer comes back.
Medical advances will probably reduce the risk of rejection and the harshness of side effects. At the same time, more people are learning about the importance of organ donation.
Recently living donors have given a part of their liver for a transplant to a close family member. This can work, but it carries risks for the donor. About 300 of these types of transplants are done in the United States each year. Only a small percent are for people with liver cancer.
Radiation Therapy
Radiation therapy is treatment that uses high-energy rays (such as x-rays) to kill or shrink cancer cells. External beam radiation delivers radiation from outside the body to the cancer. Although liver cancer cells can be killed by radiation, this treatment can’t be used at very high doses because normal liver tissue is also killed. This type of radiation may be used to shrink a liver tumor or to provide relief from symptoms such as pain, but it does not cure the liver cancer and may not help people to live longer.
A newer type of radiation treatment uses computers to map the exact location of a tumor. This lowers the damage to normal tissue and allows higher doses to be used.
Also, studies are going on to find out if using radiation along with certain chemotherapy drugs might work in treating liver cancer.
Chemotherapy
Chemotherapy refers to the use of drugs to kill cancer cells. Usually the drugs are given into a vein or by mouth. Once the drugs enter the bloodstream, they spread throughout the body. This makes them useful for cancer that has spread to distant organs.
Liver cancer does not respond to most chemotherapy drugs. The most successful single drug has been doxorubicin (Adriamycin). But most studies have not shown that chemotherapy helps liver cancer patients to live longer.
Chemotherapy can have side effects such as the following:
- nausea and vomiting
- loss of appetite
- hair loss
- mouth sores
- a higher chance of infection (from a shortage of white blood cells)
- bleeding or bruising after small cuts or injuries (from a shortage of blood platelets)
- tiredness and shortness of breath (from low red blood cell counts)
Informations obtained from National Institute of Health.