DISEASE CHARACTERISTICS: - Histologically confirmed newly diagnosed hepatoblastoma - All stages* and all histologic variants allowed NOTE: *Patients with Stage I or II disease must have specimens submitted for rapid central pathology review by Day 14 after initial surgical resection - Patients are assigned to the following risk groups: - Very low-risk: grossly resected tumors (stage I) with PFH AND an elevated AFP level > 100 ng/mL - Low-risk: grossly resected tumors (stage I-II) AND lacking any unfavorable biologic feature (i.e., any SCU elements or a low diagnostic AFP level < 100 ng/mL) - Intermediate-risk: gross residual disease/unresectable disease OR grossly resected disease with any SCU elements but no metastatic disease and no low diagnostic AFP level < 100 ng/mL - High-risk: metastatic disease OR low diagnostic AFP level < 100 ng/mL regardless of stage PATIENT CHARACTERISTICS: - ECOG performance status 0-2 - ANC* > 750/μL - Platelet count* > 75,000/μL - Creatinine clearance* or radioisotope glomerular filtration rate* ≥ 70 mL/min OR serum creatinine* based on age/gender as follows: - 1 month to < 6 months: 0.4 mg/dL - 6 months to < 1 year: 0.5 mg/dL - 1 to < 2 years: 0.6 mg/dL - 2 to < 6 years: 0.8 mg/dL - 6 to < 10 years: 1 mg/dL - 10 to < 13 years: 1.2 mg/dL - 13 to < 16 years: 1.5 mg/dL (male) or 1.4 mg/dL (female) - ≥ 16 years: 1.7 mg/dL (male) 1.4 mg/dL (female) - Total bilirubin* < 1.5 times upper limit of normal (ULN) for age - SGOT (AST)* or SGPT (ALT)* < 10 times ULN for age - Shortening fraction** ≥ 27% by echocardiogram - Ejection fraction** ≥ 47% by radionuclide angiogram (MUGA) - Not pregnant or nursing - Negative pregnancy test - Fertile patients must use effective contraception NOTE: *Organ function requirements are not required for enrolled patients who are stage I, PFH and will not be receiving chemotherapy NOTE: **For intermediate- and high-risk patients who will be assigned to protocol chemotherapy PRIOR CONCURRENT THERAPY: - Prior surgical resection of some or all sites of hepatoblastoma allowed - No prior chemotherapy for hepatoblastoma or other hepatoblastoma-directed therapy (e.g., radiation therapy, biologic agents, local therapy [embolization, radiofrequency ablation, laser]) - No other prior chemotherapy - No concurrent radiotherapy