ARM I: Patients receive cytarabine IV continuously on days 1-7 and daunorubicin IV over 5-10 minutes followed by etoposide IV over 2 hours on days 1-3. Patients with 20% or greater bone marrow cellularity and greater than 5% leukemia blasts at the end of the first course receive a second course of cytarabine IV continuously on days 1-5 and daunorubicin IV over 5-10 minutes followed by etoposide IV over 2 hours on days 1 and 2.