Hepatoblastoma is a rare, malignant (cancerous) tumor of the liver.
It is found 90% of the time before three years of age.
The cause of hepatoblastoma is usually unknown. Some genetic disorders put a child at greater risk.
An increased swelling of the belly is the most common symptom. The enlarged liver can sometimes be felt by your child’s doctor. Symptoms include:
- Swollen belly; a large mass in the belly
- Pain in the belly
- Pale skin and/or fatigue
- Lower appetite and weight loss
- Back pain
- Decreased urination
Hepatoblastoma tumors usually secrete a protein called alpha-fetoprotein (AFP) into the blood. An increase of this protein level in the blood is helpful in making the diagnosis. Imaging test such as ultrasound, CT scan, and MRI of the abdomen may also be performed.
A definitive diagnosis is made by biopsy or removal of the tumor. A biopsy is a surgical procedure where a part of the suspicious mass is removed and looked at under a microscope. These procedures are done under general anesthesia so that the child is not conscious and will not feel any pain.
Staging depends on the extent of liver involvement and whether the tumor is in only one place or if it has spread. The most common sites for metastasis or spread of tumor are the lungs and abdominal lymph nodes.
There are two staging systems for hepatoblastoma:
- The pre-treatment extent of disease (PRETEXT) staging system is based on imaging of the liver before surgery is attempted. There are four main lobes of the liver. The PRETEXT stage corresponds to the number of lobes that have tumor in them. For example, if one lobe is involved, the disease is considered stage I. If all four lobes are involved, the disease is considered stage IV.
- The Children’s Oncology Group (COG) staging system is based on additional imaging of other parts of the body, as well as the results of surgery, if surgery was performed at diagnosis. COG staging reflects how much of the tumor was removed and how much the tumor has spread.
- Stage I: There is no spread of tumor detectable outside of the liver. The tumor has been surgically removed at diagnosis and there are no cancer cells on the edges, or margins, of the removed tissue. A pathologist determines if the margins are clear of cancer cells by looking at the removed tissue under a microscope.
- Stage II: There is no spread of tumor detectable outside of the liver. The tumor has been surgically removed at diagnosis, but the margins of the removed tissue contain cancer cells.
- Stage III: The tumor cannot be surgically removed at diagnosis because it is too big, it has grown into or presses on vital tissues in the liver, or it has spread to the lymph nodes that drain from the liver. In stage III disease, the tumor is not detectable in other parts of the body besides the liver and possibly the lymph nodes close to the liver.
- Stage IV: The tumor has obvious spread through the bloodstream to other parts of the body, most commonly to the lungs.
There are several ways to treat hepatoblastoma. Treatment options might include chemotherapy, surgery to remove the tumor (also called tumor resection), and liver transplantation.
Many factors are considered when designing a treatment plan for an individual infant or child, and all treatment options should be discussed thoroughly between the care team and the family. Do not be afraid to ask questions and take an active role in the treatment plan for your child.
There has been dramatic improvement in outcomes over the last 20-25 years, from a 10% 5-year survival rate to a 80% 5-year survival rate overall. This is largely due to the coordinated use of resection, chemotherapy and in some cases liver transplantation.
The prognosis for an individual depends on the stage of the disease:
- Stage I and II: When tumors are only located in the liver and can be surgically removed at diagnosis, the published cure rate is greater than 85% when surgery and chemotherapy are used together.
- Stage III: When tumors are located only in the liver but cannot be surgically removed at diagnosis, the published cure rate is not as high, approximating 60-70%. The cure rate is higher if complete surgical removal of all tumor becomes possible. Anecdotally, the cure rate appears to be increasing for children with Stage III disease, at least in part due to increasing availability of liver transplantation as a surgical option.
- Stage IV: When tumors are located in several places in the body, the published cure rate is 20-30% using surgery and chemotherapy. There is preliminary evidence to suggest that the cure rate may be increasing for children with Stage IV disease, possibly due to more aggressive chemotherapy options and the increasing availability of liver transplantation.