Liver Cancer

Overview

Cancer occurs when cells in the body (in this case liver cells) divide without control or order. Normally, cells divide in a regulated manner. If cells keep dividing uncontrollably when new cells are not needed, a mass of tissue forms, called a growth or tumor. Not all tumors are cancerous. The term "cancer" refers to malignant tumors, which can invade nearby tissues and spread to other parts of the body. A benign tumor does not invade or spread; it is not cancerous.

(You might also hear your doctor refer to liver cancer as malignant hepatoma, hepatocellular carcinoma, or primary liver cancer.)

The cause of liver cancer is not known. It is not common in the United States among adults, and in children it is even rarer. Unlike cancers of adults, childhood cancers are not significantly related to lifestyle-related risk factors such as tobacco or alcohol use, poor diet, or not enough physical activity. However, other risk factors may contribute to childhood liver cancer.

Infection with the hepatitis B virus or the hepatitis C virus is associated with liver cancer. Cancer may not develop until years after exposure to these types of hepatitis. In other parts of the world where hepatitis B and hepatitis C are prevalent, liver cancer is much more common. Exposure to certain toxic chemicals also increases the risk of liver cancer.

There are two types of cancer that start in the liver, hepatoblastoma and hepatocellular cancer. Hepatoblastoma liver cancer is more common in young children before age three and may be hereditary. Hepatocellular liver cancer is found in children from birth to 19 years of age. Children who have hepatitis B or C are more likely than other children to get hepatocellular liver cancer. Immunization to prevent hepatitis B may decrease the chance of developing hepatocellular liver cancer.

Symptoms

Symptoms of liver cancer in the early stages are vague and often go unnoticed. Liver cancer can cause the following symptoms:

• Loss of appetite
• Unexplained weight loss
• Fever
• Fatigue
• Weakness
• Pain in abdomen
• Swollen abdomen
• Nausea
• Dark urine
• Yellowing of the skin and/or the whites of the eyes

These symptoms may also be caused by other, less serious health conditions. A person experiencing these symptoms should see a doctor.

Diagnosis

Your child's doctor will ask about your child's symptoms and review his or her medical history, as well as performing a physical examination. If the doctor suspects liver cancer, he or she will recommend tests to confirm or rule out the diagnosis. Tests may include:

• Blood tests – These can measure how well your child's liver is functioning, or find substances in the blood that signal liver cancer may be present. Most hepatoblastomas and some hepatocellular carcinomas produce a chemical called alpha-fetoprotein (AFP), which is released into the bloodstream. By measuring levels of AFP in your child's blood, doctors can sometimes tell whether the cancer is responding to treatment.
• X-rays of the chest and abdomen
• Angiograms – X-rays of blood vessels
• MRI scan – a test that uses magnetic waves to make pictures of the inside of the liver
• Ultrasound – another method of getting images of the liver and other internal organs, this test uses high-frequency sound waves
• CT scan – a type of X-ray that uses a computer to make pictures of the inside of the liver
• Laparoscopy – doctors make a tiny incision in the abdomen and insert a thin, lighted tube to look at the liver
• Biopsy – removal of a sample of liver tissue to test for cancer cells. Usually performed using a special hollow needle or during a laparoscopy procedure.

Once liver cancer is found, more tests will be done to find out if cancer cells have spread to other parts of the body. Doctors call this process "staging" because they need to find out what stage the cancer is in. Once they have that information, your child's doctors can plan the best treatment for your child. The following stages are used for childhood liver cancer:

• Stage I Liver Cancer – The cancer can be removed with surgery.
• Stage II Liver Cancer – Most of the cancer may be removed in an operation but very small (microscopic) amounts of cancer are left in the liver following surgery.
• Stage III Liver Cancer – Some of the cancer may be removed in an operation, but some of the tumor cannot be removed and remains either in the abdomen or in the lymph nodes.
• Stage IV Liver Cancer – The cancer has spread from the liver to other parts of the body.
• Recurrent Liver Cancer – The disease has come back (or recurred) after having been treated. It may reappear in the liver or in another part of the body.

Treatment

Treatments for childhood liver cancer depend on the type (hepatoblastoma or hepatocellular carcinoma) and stage of your child's disease, as well as your child's age and general health.

Surgery may be used to take out the cancer and part of the liver where the cancer is found. Surgery may also be used to remove any cancer that has spread to other parts of the body.

For some patients with earlier stages of liver cancer (particularly hepatocellular cancer), liver transplantation may be an option. Surgeons can replace the liver with a donor's healthy liver. Your child's doctor will discuss this option with you if it is a feasible treatment.

Chemotherapy uses drugs to kill cancer cells. Your child may receive chemotherapy before surgery to help reduce the size of the liver cancer, or after surgery to kill any remaining cells. Chemotherapy given after surgery when the doctor has removed the cancer is called adjuvant chemotherapy. Chemotherapy for childhood liver cancer is usually put into the body through a needle in a vein or artery. This type of chemotherapy is called a systemic treatment because the drug enters the bloodstream, travels through the body, and can kill cancer cells outside the liver. In another type of chemotherapy, called direct infusion chemotherapy, drugs are injected directly into the blood vessels that go into the liver.

A special treatment called chemo-embolization is sometimes used to treat childhood liver cancer. Chemotherapy drugs are injected into the main artery of the liver with substances that block or slow the flow of blood into the cancer. This lengthens the time the drugs have to kill the cancer cells and it also prevents cancer cells from getting the oxygen and nutrients they need to grow.

Radiation therapy uses X-rays or other high-energy rays to kill cancer cells and shrink tumors. Radiation may come from a machine outside the body (external radiation therapy) or from putting materials that produce radiation through thin plastic tubes in the area where the cancer cells are found (internal radiation therapy).

Treatment that uses medications or substances made by the body to increase or restore the body's natural defenses against cancer is called biological therapy, or biological response modifier (BRM) therapy.

Once treatment is completed, your child will have regular blood tests to measure the level of alpha-fetoprotein (if appropriate), as well as scans and chest X-rays. This allows your child's doctors to monitor the effectiveness of the treatment and catch any recurrence of cancer early.

Like his or her treatment plan, your child's chance of recovery (prognosis) depends on the stage of liver cancer (particularly whether or not it has spread), how the cancer cells look under a microscope (the histology), and your child's general state of health. As with most cancers, cure rates for children are much higher than for adult cancers. More than half of the children with hepatoblastoma are cured, and for children with small tumors only in the liver the prospects are even better.