Results of a pilot study for the treatment of childhood acute nonlymphoblastic leukemia.

Eighteen children with acute nonlymphoblastic leukemia were entered on a pilot protocol. The drugs used were vincristine, daunorubicin, cytosine arabinoside, and prednisolone for remission induction, high-dose cyclophosphamide together with vincristine and mercaptopurine for consolidation, and cycles of vincristine, prednisolone, mercaptopurine, methotrexate, and daunorubicin for maintenance therapy. Prophylactic central nervous system therapy (cranial radiotherapy 2400 rad and intrathecal methotrexate 10 mg/m2 for five doses) was given once remission had been achieved. Fourteen of the 18 children (78%) achieved complete remission (CR) and 50% of those achieving CR remain in CR for 35+ to 87+ months. Survival for all children ranges from 2 to 88+ months with 50% remaining alive for 36+ to 88+ months. The protocol was well tolerated with minimal side effects. These results together with those of other recently reported studies indicate an improving prognosis for acute nonlymphoblastic leukemia in childhood.