Hepatoblastoma throughout SIOPEL trials - clinical lessons learnt.

International Childhood Liver Tumors Strategy Group (SIOPEL) introduced the concept of preoperative chemotherapy in hepatoblastoma, most common malignant liver tumor in children. This required introduction of the preoperative tumor staging system called PRETEXT. SIOPEL 1 study proved the value of preoperative chemotherapy consisting of cisplatin and doxorubicin (PLADO) in hepatoblastoma leading to 5-year overall survival of 75 % and event-free-survival of 66 %. Both presence of metastases and PRETEXT were significant prognostic factors which led to development of two risk categories: standard (SR) and high risk (HR) hepatoblastomas. In SIOPEL 2 study two different strategies were developed for SR and HR tumors with corresponding 3-year overall and progression-free survival of 91 % and 89 %, and 53 % and 48 % respectively. In the next SIOPEL 3 SR arm study monotherapy regimen based on CDDP alone was non-inferior to PLADO for SR hepatoblastoma and less toxic. Cisplatin-based chemotherapy in combination with delayed definitive surgery / liver transplantation improved the survival of children with hepatoblastoma. However certain patients, especially those with metastatic disease and low alphafetoprotein still have inferior prognosis.