All patients receive induction chemotherapy comprising cyclophosphamide IV over 6 hours on days 0 and 1, doxorubicin IV and vincristine IV continuously over 72 hours on days 0-2, and filgrastim (G-CSF) subcutaneously (SC) or IV beginning on day 3 and continuing until blood counts recover for courses 1, 2, 4, and 6. Treatment alternates with courses 3 and 5 comprising etoposide IV over 2 hours on days 0-2, cisplatin IV over 1 hour on days 0-3, and G-CSF SC or IV beginning on day 4 and continuing until blood counts recover. Induction chemotherapy repeats every 3 weeks or when blood counts recover in the absence of disease progression or unacceptable toxicity.