Acute nonlymphocytic leukemia.

The discovery of cytosine arabinoside, and then the anthrocycline antibiotics, 6-thioguanine, vincristine, cyclophosphamide, and other drugs, has added to the armamentarium of known effective agents. The use of combination chemotherapy, the recognition of the need during induction for virtual marrow aplasia to obtain a remission, and recognition of the predilection of the disease for the central nervous system requiring prophylaxis constitute major advances. The impediment to long-term survival is the lack of effective maintenance therapy.