What Is Hepatoblastoma?

Hepatoblastoma (HBL) is a type of liver tumour that is almost exclusively found in young children. It occurs most often within the first two years of life¹ and is a primary malignant (cancerous) tumour. The liver is made up of two lobes and fills the upper right side of the abdomen, safely enclosed in the rib cage. A few functions include:

• Bile production to help digest fats in our ingested food
• Storage of glycogen (sugar) as a source of energy
• Filtering  harmful substances from the blood so they can be removed from the body via stool and urine

Generally, HBL is sporadic, meaning it occurs randomly. However, some may be associated with constitutional genetic abnormalities and malformations. Over the last three decades, the annual incidence of HBL in children has gradually increased as more pre-term babies are now surviving.²

Causes of hepatoblastoma

The exact cause of hepatoblastomas is unknown. Extremely premature babies with a birth weight of  990 g and below are known to have an increased risk of developing HBL. As medical management for premature babies has improved, this has led to a higher survival rate. This  may account for the increased annual incidence of HBL.²

The risk factor of a disease is anything that increases the chances of getting the disease. It is not absolute that any child with one or more of these risk factors will develop HBL, and  HBL may still develop in some children who do not have any known risk factors. Reach out to your child’s doctor if you think your child may be at risk.

The following conditions are among the risk factors for hepatoblastoma:

1. Aicardi syndrome
2. Beckwith-Wiedemann syndrome
3. Hemihyperplasia
4. Familial adenomatous polyposis (FAP)
5. Glycogen storage disease
6. A very low weight at birth
7. Simpson-Golabi-Behmel syndrome
8. Genetic changes like trisomy 18

Routine screening tests like an abdominal ultrasound scan and checking the level of alpha-fetoprotein in the blood can be done for children at risk of developing HBL before any symptoms appear.  These should be done routinely until the child is 4 years old.³

Signs and symptoms of hepatoblastoma

Initially, HBL is asymptomatic, meaning symptoms cannot be seen; however, signs and symptoms begin to manifest as the tumour grows larger. Seek medical attention for your child if they experience any of the following: 

• A painful lump or swelling in the abdomen 
• Unintended weight loss 
• Appetite loss
• Nausea and vomiting
• Easy fatigue
• Yellowish discolouration of the skin or whites of the eyes (jaundice)
• Fever
• Itchy skin
• Enlarged veins on the belly^{3, 4}

Management and treatment for hepatoblastoma

Treatment of  HBL involves consulting with a multidisciplinary team. Management should be planned by a team of healthcare providers who are experts in treating HBL. 

Specialists may include the following:

• Paediatric oncologist - cancer specialist for children 
• Paediatric surgeon
• Radiation oncologist
• Paediatric nurse specialist
• Rehabilitation Specialist
• Psychologist
• Social worker
• Nutritionist

1. Surgery: This involves removing the part of the liver where cancer is found or, in extreme cases, the entire liver.  It can also include removing cancer that has spread outside of the liver and to nearby tissues such as the lungs or brain.
2. Chemotherapy:  Using drugs to stop the growth of cancer cells. It is either by killing the cells or by stopping the growth of the cancer cells. Neoadjuvant therapy is given before surgery to shrink the tumour, while Adjuvant is given after surgery to prevent a recurrence
3. Watchful waiting: Watch and closely monitor the patient's health status without giving any intervention until signs or symptoms appear or change.
4. Radiation therapy: Usage of high-energy X-rays or other types of radiation to kill cancer cells or keep them from growing.³

Diagnosis

Diagnosis of HBL begins with conducting a physical exam and looking at the health history of the child.

Other investigations include:

1. Serum tumour marker test: There is an increased amount of beta-human chorionic gonadotropin (beta-hCG) hormone or alpha-fetoprotein (AFP) in the blood of children who have liver cancer. 
2. Complete blood count (CBC): This shows the full status of the blood
3. Liver function tests: Determine the state of the liver using the blood
4. Blood chemistry studies: These blood tests measure the amounts of bilirubin or lactate dehydrogenase (LDH), released into the blood as a result of the cancer 
5. Epstein-Barr virus (EBV) test: This blood test checks if patients have been infected with EBV.
6. Imaging
   • Magnetic resonancethe imaging (MRI): Show the imaging of internal organs
   • CT scan (CAT scan): ENLARGE
   • Abdominal ultrasound
   • Abdominal X-ray

7. Biopsy: a sample of cells or tissue is removed and sent for Immunohistochemistry.

Complications

The survival of children with HBL has improved significantly since the introduction of effective cancer treatments and newer surgical approaches. These have resulted in an increase in the number of patients undergoing definitive tumour resection and a reduction in the incidence of postsurgical recurrences.⁶

However, complications may include:

• Bleeding as a result of surgery
• Susceptibility to infections, bruising and bleeding, vomiting, diarrhoea, hair loss, and tiredness due to chemotherapy
• Problems with growth and development
• Heart, kidney, or lung problems
• Problems with liver function
• Metastasis (spreading of cancer)
• Regrowth of cancer 
• New cancers occurring later in life
• Rejection of the transplanted liver

FAQs

How can I prevent hepatoblastoma?

The exact cause of hepatoblastoma is unknown and, therefore, can not be prevented. 

How common is hepatoblastoma?

Hepatoblastoma is a relatively rare type of cancer, accounting for about 1-2% of all childhood cancers. It typically occurs in children between the ages of 0 and 3, with the highest incidence during the first year of life. The exact prevalence can vary among different populations and regions.

Who is at risk of hepatoblastoma?

Children who were born prematurely with a low birth weight,  early exposure to hepatitis B infection, and biliary atresia.

While the exact causes of hepatoblastoma are not fully understood, certain risk factors have been identified. Children with certain genetic conditions, such as familial adenomatous polyposis (FAP) and Beckwith-Wiedemann syndrome (BWS), have an increased risk of developing hepatoblastoma. Additionally, infants born prematurely or with a low birth weight may also have a slightly higher risk. However, it is important to note that the majority of children diagnosed with hepatoblastoma do not have any known risk factors

When should I see a doctor?

You should see your doctor if you notice a change that is not normal for you.

Summary

Hepatoblastoma is a rare type of liver cancer that primarily affects children, typically occurring in infants and young children under the age of 3. It originates from immature liver cells called hepatoblasts, which are involved in liver development during foetal growth. The exact cause of hepatoblastoma is not fully understood, but certain genetic conditions, such as Beckwith-Wiedemann syndrome, and certain birth defects, such as familial adenomatous polyposis (FAP), are associated with an increased risk of developing this cancer.

Common symptoms of hepatoblastoma may include an abdominal mass or swelling, abdominal pain, weight loss, loss of appetite, and sometimes jaundice (yellowing of the skin and eyes).

The diagnosis of hepatoblastoma typically involves imaging studies like ultrasound, CT scans, or MRI, and a biopsy to confirm the presence of cancerous cells.

Treatment for hepatoblastoma usually involves a combination of surgery, chemotherapy, and, in some cases, liver transplantation. The specific treatment plan depends on the extent and stage of the cancer and the overall health of the child.

With advances in medical care, the prognosis for hepatoblastoma has improved over the years. The outcome varies depending on the stage of diagnosis and the effectiveness of treatment, with a higher chance of successful outcomes when detected and treated early. A multidisciplinary approach involving paediatric oncologists, surgeons, and other specialists is crucial for managing hepatoblastoma successfully. Regular follow-ups and monitoring are essential to detect any recurrence or late effects of treatment.