What is Hepatoblastoma?
Hepatoblastoma is a rare, malignant (cancerous) tumor of the liver. It is found 90 percent of the time before 3 years of age.
The cause of hepatoblastoma is most often not known. 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.
Most Common Symptoms
- 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 is often first suspected when there is a large mass in the belly. The initial diagnosis can be made using imaging and blood tests.
Hepatoblastoma tumors often 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 tests such as ultrasound, CT scan and MRI of the belly may also be done.
A final diagnosis is made by biopsy or removal of the tumor. A biopsy is a surgery where a part of the mass is removed and looked at under a microscope. These procedures are done under general anesthesia so that the child is not awake and will not feel any pain.
Stages of Hepatoblastoma
Staging depends on the extent the liver is involved 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 lymph nodes around the belly.
There are two staging systems for hepatoblastoma.
- The pre-treatment extent of disease (PRETEXT) staging system: This is based on imaging of the liver before surgery is tried. There are four main lobes of the liver. The PRETEXT stage depends on the number of lobes that have a tumor in them. For instance, if one lobe is involved, the disease is called stage I. If all four lobes are involved, the disease is called stage IV.
- The Children’s Oncology Group staging system: This is based on more imaging of other parts of the body, as well as the results of surgery if done 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 that can be found outside of the liver. The tumor has been removed through surgery at diagnosis. A pathologist looks at the removed tissue under a microscope to find out if the margins are clear of cancer cells. There are no cancer cells on the edges, or margins, of the removed tissue.
Stage II: There is no spread of tumor that can be found outside of the liver. The tumor has been removed through surgery at diagnosis, but the margins of the removed tissue contain cancer cells.
Stage III: The tumor cannot be removed with surgery 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 cannot be found in other parts of the body. It is only found in the liver and sometimes the lymph nodes close to the liver.
Stage IV: The tumor has spread through the bloodstream to other parts of the body. It often spreads to the lungs.
There are a few ways to treat hepatoblastoma. This may include chemotherapy, surgery to remove the tumor (also called tumor resection) and liver transplantation.
Chemotherapy (Chemo) is a key part of treatment for nearly all infants and children with hepatoblastoma. Chemo is used to both shrink the primary liver tumor, and to treat any hepatoblastoma that has escaped outside the liver. This is needed for patients with all stages of the disease, because cancer cells might have traveled to other parts of the body. These cancer cells may be in amounts too small to be found by doctors. Infants and children with COG stage I disease of a less aggressive type called pure fetal hepatoblastoma may not need chemo. For all other infants and children, chemo is given before and / or after surgery.
Tumor removal / resection: Many factors are looked at when checking if a tumor can be safely removed from a child’s liver leaving enough normal liver. One of the factors that doctors look at is the degree that the liver is involved. For instance, some children have a single tumor, while other children have multifocal disease (more than one tumor in the liver). Some tumors involve just one or two liver lobes, while others involve three or four liver lobes. Some tumors encroach upon vital structures within the liver, while others do not invade such structures. Tumor resection (removal) can be discussed at diagnosis for patients with limited disease at this point. This is true for around a third of children with hepatoblastoma. Of the children whose tumors are not resectable at diagnosis, their tumors can sometimes become resectable after a few cycles of chemo.
Liver transplantation has also been used with success with chemo to treat hepatoblastoma. Liver transplants are most often used in cases where the tumor is only in the liver and is not able to be removed by surgery. In these cases, the liver with the tumor is fully removed and replaced with a liver from a donor. Like with other surgeries for hepatoblastoma, chemo is used before and often after liver transplant to control the cancer. In some cases, infants and children who have hepatoblastoma that cannot be resected by normal surgery and have cancer outside of their liver (aggressive COG stage IV disease), can still have a liver transplant with success. An example of when this may be possible is when the disease outside the liver goes away with chemo.
Many factors are looked at when making a treatment plan for each child. The care team and the family should discuss all options fully. Do not be afraid to ask questions and take an active role in the treatment plan for your child.
Outcomes have greatly improved over the last 20 to 25 years. Survival rates have reached 80-90 percent. This rate depends upon staging at diagnosis. Patients with fully resected tumors have a greater than 85 percent chance of survival. The rate is about 60 percent for those with metastatic disease that responds to chemo.
The outlook depends on the stage of the disease:
- Stage I and II: Tumors are only in the liver and can be removed through surgery at diagnosis. The published cure rate is greater than 90 percent when using surgery and chemo.
- Stage III: Tumors are only in the liver but cannot be removed through surgery at diagnosis. The published cure rate is not as high, around 90 percent. The cure rate is higher if full removal of all tumor through surgery becomes an option. The cure rate appears to be increasing for children with Stage III disease. This seems to be, at least in part, due to liver transplants becoming more of an option.
- Stage IV: Tumors are in several places in the body. The published cure rate is 50 percent to 60 percent using surgery and chemo. There is starting to be evidence to suggest that the cure rate may be getting better for children with Stage IV disease. This may be due to more aggressive chemo options, and liver transplant being more available.