What is Hepatoblastoma
Hepatoblastoma is the most common liver tumor in children, with a higher incidence from 0 to 4 years old, being rare after 5 years of age. The cells of hepatoblastoma are similar to fetal liver cells. About two out of three children with these tumors are successfully treated with surgery and chemotherapy.
In recent decades, there has been significant advancement in the management of hepatoblastoma due to improvements in diagnostic imaging methods, the use of effective chemotherapy regimens, better surgical approaches, and the possibility of liver transplantation.
Symptoms of hepatoblastoma
The signs of infantile hepatoblastoma can vary in each child and depend on the extent of the tumor and whether there are distant metastases or not. Some patients present early puberty associated with an increase in human chorionic gonadotropin (BetaHCG). Overall, the symptoms are:
- Abdominal swelling (which can be painful);
- Unexplained weight loss;
- Loss of appetite;
- Nausea;
- Vomiting;
- Jaundice;
- Fever;
- Anemia.
Diagnosis of hepatoblastoma
The diagnosis and treatment are based on risk stratification of patients, with an evaluation of serum tumor biomarkers, imaging studies (to study the extent of the disease), and histopathology.
To arrive at the diagnosis of hepatoblastoma, it is necessary to perform:
- Laboratory tests – alpha-fetoprotein is a tumor marker that is elevated in patients with hepatoblastoma. This marker, measured in blood tests, also helps in evaluating the response to chemotherapy and surgery. Other blood tests should be requested, such as complete blood count, liver function tests, and tests for hepatitis and Epstein-Barr virus (EBV);
- Imaging exams – abdominal ultrasonography with Doppler is the requested exam for the identification of liver tumors. Contrast-enhanced computed tomography and abdominal magnetic resonance imaging are also essential for evaluating the liver tumor. Chest computed tomography is used to assess the presence of lung metastases;
- Angiography – is an X-ray exam that examines blood vessels. A contrast (or dye) is injected into an artery to outline the blood vessels while X-ray images are taken. Angiography can be used to show the arteries that supply blood to the liver cancer, which can help doctors decide if the cancer can be removed, and to help plan the operation. It can also guide some types of non-surgical treatment, such as embolization; and
- Biopsy – is the removal of a tissue sample to check for cancer cells. Often, imaging and blood tests can already confirm this type of cancer. Nevertheless, in some cases, a biopsy may be necessary for confirmation of the neoplasm.
Treatment for hepatoblastoma
The treatment approach for hepatoblastoma according to the SIOP (International Society of Pediatric Oncology) protocol involves a multimodal approach, including preoperative chemotherapy (aimed at reducing the primary tumor), followed by surgical resection of the residual tumor. Patients with unresectable tumors after preoperative chemotherapy are referred for liver transplant evaluation.
Prognosis depends on the resectability, size, and location of the tumor, the extent of the disease, and the presence or absence of metastases.
Main treatment approaches for hepatoblastoma
Surgical resection (removal of the tumor with surgery) is the best option for curing hepatoblastoma. Partial hepatectomy may be performed, removing the part of the liver where the cancer is located along with a small amount of healthy tissue around it. Total hepatectomy, which involves removing the entire liver, may be indicated for some cases along with liver transplantation.
Another possibility is ablation, a treatment that destroys liver tumors without removing them. This technique can be used in patients with small tumors and when surgery is not a good option (usually due to health problems). Sometimes, it is also used in patients awaiting a liver transplant. There are different types of ablation, such as radiofrequency, microwave, or cryoablation (which destroys the tumor by freezing it).
Embolization is a procedure that injects substances directly into an artery in the liver to block or reduce blood flow to the tumor. Blocking the part of the hepatic artery that feeds the tumor helps kill cancer cells.
For tumors that cannot be removed by surgery, are treated with ablation or embolization, or have not responded well to these treatments, radiation therapy is a commonly used option.
Finally, chemotherapy is indicated in all cases of hepatoblastoma in children. It is usually administered before surgery to reduce the tumor and make it easier to remove.
Prevention of Hepatoblastoma
The exact cause of liver cancer in children is unknown. However, it is known that prematurity and low birth weight are associated with the risk of developing the disease. Since these factors are not controllable by patients, there is no way to prevent hepatoblastoma.
