REGIMEN I (stage II BWT with blastemal predominance or stage II unilateral WT with blastemal predominance): Patients receive vincristine sulfate IV over 1 minute on days 43, 50, 57, 71, 78, 85, 92, 127, and 169 (weeks 7-9, 11-14, 19, and 25); doxorubicin hydrochloride IV over 15-120 minutes on days 43, 85, 127, and 169 (weeks 7, 13, 19, and 25); cyclophosphamide IV over 15-30 minutes on days 43, 64, 85, 106, 127, 148, and 169 (weeks 7, 10, 13, 16, 19, 22, and 25); and etoposide phosphate IV over 1 hour on days 64, 106, and 148 (weeks 10, 16, and 22).