Hepatoblastoma: Diagnostic Work-up and Treatment Approach
The gold standard treatment for hepatoblastoma is perioperative cisplatin-based chemotherapy followed by complete surgical resection of all viable tumor. 1
Immediate Diagnostic Work-up
Obtain serum alpha-fetoprotein (AFP) at presentation, which is typically markedly elevated (often >1,000 ng/dL) in hepatoblastoma and serves as both a diagnostic marker and monitoring tool. 2, 3
Perform contrast-enhanced abdominal CT or MRI with multiphasic technique to characterize the mass, evaluate vascular involvement, and define disease extent. 2, 4
Obtain chest CT to detect pulmonary metastases, which is essential for staging and treatment planning. 2, 4
Apply PRETEXT (Pretreatment Extent of Disease) staging at diagnosis to gauge extent of disease and triage patients for early referral to a program with experience in both pediatric hepatobiliary surgery and liver transplantation. 1
Risk Stratification and Immediate Referral Decisions
Children with nonmetastatic and otherwise unresectable hepatoblastoma should be referred for liver transplant evaluation at the time of diagnosis or no later than after 2 rounds of chemotherapy. 1, 5, 2
High-risk features requiring immediate transplant center referral include:
- PRETEXT IV disease (disease involving all four sections of liver) 1
- Complex PRETEXT III disease (multifocal or presence of venous thrombosis) 1
- Centrally located tumors whose location makes tumor-free excision unlikely 1
These patients have poor outcomes with chemotherapy and surgical resection alone. 1
Initial Treatment Protocol
Initiate cisplatin-based chemotherapy immediately after diagnosis according to the Children's Oncology Group protocol (COG-AHEP0731). 1, 5
Administer sodium thiosulfate (16-20 g/m²) 6 hours after each cisplatin dose to prevent ototoxicity without compromising survival in non-metastatic disease. 5, 6
Reassess tumor resectability after 2-4 cycles of chemotherapy using repeat imaging. 1, 5
Surgical Decision Algorithm After Chemotherapy
After 2-4 cycles of chemotherapy, proceed according to this hierarchy:
If complete resection with negative margins is achievable: Perform conventional hepatic resection. 5, 2
If tumor remains unresectable but confined to liver: Proceed to primary liver transplantation, which achieves 82% 10-year survival compared to only 30% 10-year survival for "rescue" transplantation after failed resection. 1, 5
If tumor becomes resectable after additional chemotherapy cycles: Continue chemotherapy up to 6 cycles total before attempting resection, but do not delay beyond this without definitive surgery. 7, 8
Management of Metastatic Disease
Patients with pulmonary metastases at diagnosis can be considered for liver transplantation if, following chemotherapy, either of the following occurs:
- Pulmonary metastases are no longer seen by chest CT, OR
- Residual pulmonary metastases are completely resected with tumor-free margins 1, 5, 2
These patients have recurrence-free survival following liver transplantation that is similar to those without pulmonary metastases at diagnosis. 1
Critical Pitfalls to Avoid
Do not delay transplant referral beyond 2 chemotherapy cycles for clearly unresectable disease, as this substantially reduces survival advantage from 82% to 30% at 10 years. 1, 5, 2
Do not attempt aggressive conventional resection with anticipated positive margins, as this converts a primary transplant candidate (82% survival) into a rescue transplant candidate (30% survival). 1, 5, 2
Do not exclude patients with pulmonary metastases from curative intent, as they can achieve excellent outcomes with complete resection of metastases after chemotherapy, equivalent to non-metastatic disease. 1, 5, 2
Do not perform liver biopsy when imaging and AFP are diagnostic, to prevent tumor seeding and unnecessary procedural risk. 2
Multidisciplinary Team Requirements
All children with hepatoblastoma should receive coordinated management at a pediatric liver transplant center involving:
- Pediatric gastroenterologist with expertise in liver disease 1, 2
- Pediatric hepatobiliary surgeon 1, 2
- Liver transplant surgeon 1, 2
- Pediatric oncologist 2, 6
- Pediatric intensive care specialist 1, 2
This multidisciplinary approach optimizes patient outcomes and ensures timely decision-making regarding surgical versus transplant options. 1, 2