Table 1

Modified COG Evans staging system (CCCG-HB-2016)6

Stage	Definition
Stage Ia	Complete resection, PFH.
Stage Ib	Complete resection, non-PFH.
Stage II	Incomplete resection with microscopic residue.
Stage III	Incomplete resection with macroscopic residue. Incomplete resection with positive lymph nodes. Tumor rupture or intraperitoneal bleeding.
Stage IV	Distant metastasis at diagnosis, whether primary lesion resection or not.

CCCG-HB-2016, Chinese Anti-Cancer Association Pediatric Committee Hepatoblastoma consensus 2016; COG, Children’s Oncology Group; HB, hepatoblastoma; PFH, pure fetal histology.