Hepatoblastoma - Causes, Symptoms, Diagnosis and Treatment

What Is Hepatoblastoma?

Hepatoblastoma is a condition in which malignant (cancer) cells or tumors form in the tissues of the liver. It is the most common type of liver cancer occurring in children aged three years and younger. Hepatoblastoma mainly affects the right lobe of the liver.

The liver is one of the largest organs of the body. It consists of two lobes and is located on the upper right side of the abdomen inside the rib cage. The three most important functions performed by the liver are as follows-

• Production of bile for the breakdown of fats from food.

• Storage of sugar in the form of glycogen, which the body uses for energy.

• Filtration of harmful substances from the blood so that they can be removed from the body through urine and stools.

What Are the Symptoms of Hepatoblastoma?

The symptoms of hepatoblastoma vary depending on the size of the tumor and whether it has spread to any other part of the body. The symptoms do not usually show up until the tumor has grown to a considerable size, affecting the child's overall health. Symptoms can also present differently in each child. These may include-

• A lump (mass) in the abdomen (belly) that may be painful.

• Swelling of the abdomen.

• Pain in the abdomen.

• Unexplained weight loss.

• Loss of appetite.

• Feeling tired.

• Nausea and vomiting.

• Yellowing of the skin and whites of the eyes (jaundice).

• Fever.

• Itchy skin.

• Enlarged veins on the belly.

The symptoms of hepatoblastoma may resemble other health conditions, so it is essential to get a proper examination and diagnosis from a healthcare provider if these symptoms show up.

What Causes Hepatoblastoma?

The exact cause of hepatoblastoma is still unknown, but the researchers believe it occurs due to a change or alteration in a gene. But the reason for the same is unknown. However, a few risk factors, including certain hereditary conditions, have been identified that might increase the risk of developing hepatoblastoma.

Anything that increases the probability of getting the disease is termed a risk factor. Not all children having one or more of these risk factors will develop hepatoblastoma. In some children, hepatoblastoma may develop without the child having any known risk factors. Talk to the child’s healthcare provider if the child is at risk.

The following conditions and syndromes are known to be risk factors for hepatoblastoma-

• Aicardi Syndrome - Absence or underdevelopment of the tissues connecting the right and left halves of the brain.

• Beckwith-Wiedemann Syndrome - Growth disorder in children affecting several body parts.

• Hemihyperplasia - Overproduction of bones and soft tissues, causing one part or one side of the body to grow significantly larger than the other half.

• Familial Adenomatous Polyposis - Genetic disorder characterized by cancer of the large intestine.

• Glycogen Storage Disease - Inherited disorder causing glycogen to be improperly stored in the body.

• Simpson-Golabi-Behmal Syndrome - Rare congenital overgrowth disorder causing multiple abnormalities and mainly occurs in males.

• Weight: Very low weight at birth is also a cause for the development of hepatoblastoma.

Those children predisposed to developing hepatoblastoma may have other tests done to determine cancer before the appearance of any symptoms. For example, until the child turns four years old, an abdominal ultrasound exam is done every third month, along with the evaluation of the alpha-fetoprotein levels in the blood.

How Is Hepatoblastoma Diagnosed?

The tests that are used for the examination of the liver and blood are used for the diagnosis of hepatoblastoma to find out whether cancer has spread.

The following procedures and tests may be done-

• Physical Exam and Health History - A physical exam checks for a person’s health, including any signs of disease, such as a lump or anything that might seem unusual. The health history includes the health habits of the patient and any past illnesses and treatments undertaken.

• Serum Tumor Marker Test - Tumor markers are substances that are released by organs, tissues, or tumor cells into the blood, and when their levels are increased in the blood, they might be linked to some specific type of cancer. A serum tumor marker test measures the amount of these tumor markers. Children with hepatoblastoma may have increased alpha-fetoprotein (AFP) levels or the hormone beta-human chorionic gonadotropin (beta-hCG) in their blood.

• Complete Blood Count - This blood test checks for red blood cells, white blood cells, platelets, the amount of hemoglobin (a protein that carries oxygen) in the red blood cells, and the portion of the sample of the blood having red blood cells.

• Liver Function Tests - These blood tests check for the amount of certain substances released by the liver into the bloodstream. If the amount is higher than normal, it can indicate liver damage or cancer.

• Magnetic Resonance Imaging (MRI) - This procedure uses radio waves, a magnet, and a computer to produce detailed images of inside areas of the liver.

• Computed Tomography (CT) - This procedure involves a computer linked to an X-ray machine to produce images of several areas inside the body, taken at different angles. In hepatoblastoma, a CT scan of the chest and abdomen is performed.

• Ultrasound - This procedure involves using ultrasound (high-energy sound waves) to bounce off tissues or organs and produce echoes. The echoes make a picture of body tissues called a sonogram. An abdomen ultrasound is done in hepatoblastoma to check for large blood vessels.

• Biopsy - In a biopsy procedure, a sample of cells or tissues is taken. This sample is then viewed under a microscope to look for cancer cells and determine the type of cancer.

After the diagnostic procedures, specific tests are performed to check whether cancer has spread within the liver or other body parts. This process is called staging. In hepatoblastoma, two groups are assigned instead of stages– POSTTEXT and PRETEXT.

• PRETEXT- This group is assigned at the time of diagnosis. This group describes the tumor before any treatment has been done.

• POSTTEXT- This group describes the tumor after some treatment has been done.

Both groups can have a value ranging from one to four. The higher the number, the more parts of the liver are involved, which also signifies the advancement of cancer.

How Is Hepatoblastoma Treated?

Healthcare providers may recommend the following treatment options for hepatoblastoma-

• Surgery - Surgery is done for the purpose of conducting a biopsy and determining the stage of hepatoblastoma. It is also performed to remove a large amount of the tumor, if possible, and to eliminate the tumors that may have metastasized to other organs, such as the lungs.

• Chemotherapy - It involves drugs that kill cancer cells. These may be given before or after the surgery. These are administered into a vein (IV), by injection, or by mouth (oral). The drugs may also be delivered directly into the liver by using a tube (catheter) in the main artery of the liver. This procedure is called chemoembolization of the hepatic artery. The drug is mixed with a substance that blocks blood flow to the tumor. This inhibits the tumor’s growth.

• Radiation Therapy - This is a standard treatment procedure for many cancer types, but it is still under study for hepatoblastoma. This procedure involves high-energy X-rays or other forms of radiation.

• Liver Transplant - A liver transplant may be required if the liver has significant damage or the tumor size is too large to be removed through surgery.

• Clinical Trials - The child may qualify for clinical trials that may be available. Always ask the healthcare provider about the same.

• Supportive Care - It involves using certain medications and other treatments for the side effects of any of the above-described treatment procedures.

Conclusion:

Hepatoblastoma is a very rare liver cancer affecting young children less than four years of age. It can be successfully treated, but it leaves a cast of a long shadow. This cancer may recur even after successful treatment. It may also cause second cancer. Some children may also develop medical complications after years of treatment for hepatoblastoma. Always ask the child’s healthcare provider about the various challenges the child may face and find out about the most appropriate treatment option.