Prognostic stratification for children with hepatoblastoma: the SIOPEL experience.

ABSTRACT

PURPOSE: To identify factors relevant to long-term outcome in newly diagnosed hepatoblastoma, and define subgroups for clinical research on tailoring treatment to the individual patient. PATIENTS AND METHODS: Between 1995 and 2006 the SIOPEL group conducted two clinical trials which established risk-adapted therapy for hepatoblastoma patients. Patients were stratified into high-risk (AFP < 100 ng/mL and/or PRETEXT IV and/or vascular invasion and/or extra-hepatic intra-abdominal disease (V+/P+/E+) and/or metastases) and standard-risk (all others). The hierarchy of these factors plus multifocality, PRETEXT III, AFP > 1,200,000 ng/mL, patient age, platelet count and histology were further explored. The outcome measure was event-free survival (EFS). RESULTS: In 541 patients, reduced EFS correlated significantly with AFP < 100 ng/ml (hazard ratio [HR] 4.09, 95% confidence interval 2.16-7.75), AFP ≥ 1.2 × 10(6)ng/mL (2.48, 1.47-4.17), metastatic disease (3.02, 2.05-4.44), PRETEXT IV (2.15, 1.19-3.87), multifocality (1.59, 1.01-2.50), age > 5 years (2.76, 1.68-4.53); borderline with small cell undifferentiated (SCU) histology (2.29, 95% confidence interval 0.91-5.77); but not with PRETEXT III, age 30-60 months, platelet count or V+/P+/E+. By using the significant factors and SCU to stratify the population, we have identified three distinct prognostic groups PRETEXT I/II/III, and no other factors, have 3 year EFS of 90%, PRETEXT IV and/or multifocal tumour and/or age> 5 years and/or AFP > 1.2 × 10(6) have 3 year EFS of 71% and SCU and/or AFP < 100 ng/mL and/or metastatic have a 3year EFS of 49%. CONCLUSION: Prognostic stratification for clinical research on newly diagnosed hepatoblastoma should take into consideration PRETEXT, metastatic disease, AFP, multifocality, age and SCU histology.