MD2B - Pediatric Oncology: Hepatoblastoma

Overview

Hepatoblastoma is the most common type of liver cancer to occur in children. Approximately 100 new cases are diagnosed each year in the United States, accounting for 43% of all pediatric liver masses. Hepatoblastoma occurs most frequently in children under 3 years of age. It is more common in Caucasians than African- Americans, and occurs slightly more frequently in males than females.

Symptoms

Hepatoblastoma most frequently presents as a large, asymptomatic abdominal mass found by a physician on routine physical examination or discovered incidentally by a parent. As the disease progresses, weight loss, anorexia (loss of appetite), nausea, vomiting, fever, and abdominal pain may occur. Children with hepatoblastoma may develop anemia (pale skin and lips from decreased number of red blood cells) or jaundice (yellowing of the eyes and skin from elevated bilirubin).

Risk factors

Hepatoblastoma occurs much more frequently in patients with Beckwith-Wiedemann syndrome and familial adenomatous polyposis. Beckwith-Wiedemann syndrome is a condition characterized by the combination of a large tongue, large organs, large body size, umbical hernia, abdominal wall defects, and infantile low blood sugar. Familial adenomatous polyposis is an inherited disorder characterized by the presence of thousands of colon polyps which develop into colon cancer if untreated. Hepatoblastoma has also been shown to occur more frequently in premature children and those born with very low birth weight.

Diagnosis

Laboratory work

• Complete blood count (CBC) : a blood sample to evaluate the number and appearance of red blood cells, white blood cells, and platelets.
• Chemistry panel: a blood sample to evaluate liver and kidney function and to look at the levels of various chemicals in the blood
• Alpha-fetoprotein (AFP) levels : a blood sample to evaluate the amount of alpha-fetoprotein (AFP) in the blood. AFP is produced by immature liver cells, and 90% of patients with hepatoblastoma will have elevated AFP levels. AFP levels can also be followed to evaluate response to treatment and to monitor for disease recurrence.

Imaging

• X-ray : a diagnostic imaging procedure which uses electromagnetic energy beams to produce images on film of internal structures.
• U ltrasound (sonography) : a diagnostic imaging test which uses high-frequency sound waves to produce images of blood vessels and internal structures.
• Computed Tomography Scan (CT or CAT scan.) : a diagnostic imaging procedure using x-rays and computer technology to produce sliced images of the body.
• Magnetic Resonance Imaging (MRI) : a diagnostic imaging procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of internal structures.

Biopsy

A tissue sample is taken from the primary tumor to confirm diagnosis.

Treatment

Surgery and chemotherapy are the main treatment modalities for hepatoblastoma. As much as 85% of the liver can be safely removed during surgery because the remaining liver is able to regenerate itself within a few months. Any pulmonary metastases at the time of diagnosis should also be surgically removed if possible. Hepatoblastoma is very responsive to chemotherapy, so multiagent chemo regimens are initiated before surgery and continue after tumor resection. Liver transplantation has been shown to be a promising alternative for those children who have non-resectable tumors.

Prognosis

About 90% of children with respectable tumors achieve long-term survival. With tumors that can not be completely removed at diagnosis, survival rates drop to approximately 60%. When metastatic disease is present at the time of diagnosis, long- term survival occurs in only 25% of patients.