Progress in the study of therapeutic strategies for hepatoblastoma in children

Table 3 Risk stratification criteria for hepatoblastoma

Risk group	Stratification criteria
Very low risk	Postoperative COG stage I with well-differentiated fetal histology
Low risk	Meets any of the following	Serum AFP ≥ 100 ng/mL, PRETEXT stage I or II, and absence of high-risk features
		Portal vein involvement (P+)
		Inferior vena cava or hepatic vein involvement (V+)
		Distant metastasis (M+)
		Extrahepatic abdominal disease (E+)
		Tumor rupture or intraperitoneal hemorrhage (H+)
		Lymph node involvement (N+)
	Postoperative COG stage I or II with non-pure fetal and non-small-cell undifferentiated histology
Intermediate risk	Meets any of the following	Preoperative PRETEXT stage III
		Postoperative COG stage I or II with small-cell undifferentiated histology
		Postoperative COG stage III
High risk	Meets any of the following	Serum AFP < 100 ng/mL
		Preoperative PRETEXT stage IV
		Postoperative COG stage IV
		Portal vein (P+) or inferior vena cava/hepatic vein involvement (V+)

COG: Children’s Oncology Group; AFP: Alpha-fetoprotein; PRETEXT: Pre-treatment extent of disease; P⁺: Portal vein involvement; V⁺: Hepatic vein or inferior vena cava involvement; M⁺: Distant metastasis; E⁺: Extrahepatic abdominal disease; H⁺: Tumor rupture or intraperitoneal hemorrhage; N⁺: Lymph node involvement.