The liver is a large organ located in the upper right side of the abdomen, protected by the ribcage. The normal functions of the liver to help store nutrients from food, to break down and remove harmful chemicals from the body and to build chemicals that the body needs to stay healthy.When cells that make up the liver grow out of control, liver cancer may develop. There are two types of liver cancer that are the most common in children and adolescents.
- Hepatoblastoma (HB) occurs most frequently in infants and children between the ages of 2 months and 3 years. This is the most common kind of liver cancer in children.
- Hepatocellular carcinoma (HCC) occurs most frequently in children between the ages of 10 and 16.
Symptoms of Liver CancerLiver cancer most often causes enlargement of the abdomen due to the rapidly enlarging tumor. This often happens without any other symptoms. When additional symptoms do occur they may include:
- Loss of appetite
- Weight loss
- Stomach pain
- Unequal growth of one part of the body compared to another
- Early signs of puberty
Diagnosing Liver CancerA number of tests are performed to evaluate liver cancer in a child. The first test is usually an X-ray or ultrasound. Other tests that may be performed include:
- CT scan
- Magnetic Resonance Imaging (MRI)
- Blood tests
- Complete blood count (CBC)
- Alphafetoprotein (AFP) is a substance (protein) made by immature (early in development) liver cells. It is often elevated in children with liver tumors.
Determining Extent of the DiseaseIf a liver tumor is found, more tests are performed to see if the cancer cells have spread to other parts of the body. This process is called staging. There are four stages of liver cancer.
Stage I: The entire tumor was removed with surgery.
Stage II: Tumor cells are found close to the margin of normal liver tissue after the tumor has been removed with surgery. This means that there probably are a few tumor cells still left in the liver, called microscopic residual disease.
Stage III: Some of the tumor was removed with surgery, but some (or all) of the tumor could not be removed.
Stage IV: The tumor has spread to the lungs or other parts of the body.
Recurrent: The cancer has come back (recurred) after it has been treated. Liver tumors may recur in the liver or in other parts of the body.
Causes of Liver CancerIt is unclear exactly how liver cancer develops, but it is believed to develop when mistakes (mutations) occur during the growth of liver cells. These cells grow without the usual regulation of normal liver cells, leading to a tumor. Some children are diagnosed with hepatoblastoma so young that scientists believe the cancer starts before the children are born.
Hepatocellular carcinoma is seen more frequently in areas of the world that have high rates of hepatitis. Infection with any one of several viruses that cause hepatitis is believed to be responsible.
Only a few risk factors for hepatoblastoma are known for sure.
Children with some genetic syndromes are more likely to develop hepatoblastoma than other children. These syndromes are Beckwith-Wiedemann syndrome and Familial Adenomatous Polyposis. Children with these genetic conditions are more at risk for hepatoblastoma, but these account for only a small fraction of cases. These syndromes usually require medical care, so you would know if your child had one of them.
Low birth weight
Babies weighing less than 1,500 grams or about 3½ pounds at birth have a much higher risk of hepatoblastoma compared to normal weight babies. Babies that are smaller than average (3 pounds 5 ounces - 5 pounds 8 ounces) have a slightly increased risk of developing hepatoblastoma. The reasons for the high risk associated with lower birth weights are not clear. Most children who are born with low birth weight never develop hepatoblastoma.