Table 1.

International risk stratification [12]. Risk stratification of children with Hepatoblastoma (HB) reflecting the respective international treatment protocols, COG: Children’s Oncology Group; SIOPEL: International Childhood Liver Tumour Strategy Group; JPLT: Japanese Pediatric Liver Tumour Study Group; GPOH: German Society of Pediatric Oncology and Hematology; SCU: small cell undifferentiated; AFP: α-fetoprotein, V (tumor extends into the vena cava and/or all three hepatic veins), P (the main and/or both left and right branch/es of the portal vein are involved by the tumor), E (evidence of extrahepatic intra-abdominal disease), and M (distant metastases).

Risk Group	COG	SIOPEL	JPLT	GPOH
Very low risk	PRETEXT I or II, pure fetal histology and primary resection	–	–	–
Low risk/ Standard risk	PRETEXT I or II, any histology primary resection	PRETEXT I, II, III	PRETEXT I, II, III	PRETEXT I, II, III
Intermediate risk	PRETEXT II, III, IV unresectable at diagnosis V+, P+, E+ SCU	–	PRETEXT IV, any tumor with rupture, N1,P2,P2a,V3, And V3a multifocal	–
High risk	Any PRETEXT, M+, AFP < 100ng/mL	Any PRETEXT, V+, P+, E+, M+, SCU, AFP < 100 ng/mL, tumor rupture	Any PRETEXT, M1, N2, AFP < 100 ng/mL	Any PRETEXT, V+, P+, E+, M+, multifocal