[High-dose cytosine arabinoside treatment of leukemia with special reference to the optimal number of doses].

A high dose of cytosine arabinoside (ara-C) was given to 51 patients during consolidation therapy or with refractory or relapsed acute leukemia. Ara-C was administered as a 3-hour infusion at a dose ranging from 2 to 3 g/m2 every 12 hours, diluted in 500 ml of 5% dextrose in water for 2 to 6 days. Complete remission was attained in 3 (25%) of 12 evaluable patients. Two with blast crisis of chronic myelogenous leukemia of these did not obtain complete remission. Death due to marrow aplasia occurred in five patients, and two of these had relatively good performance status and were given a dose of 3.0 g/m2 x 8 or 12 of ara-C. At a dose of 3.0 g/m2 x 6, the mean duration of granulocytes of less than 100/mm3 was 6.7 days. This duration seemed to be manageable myelosuppression. Therefore, 3.0 g/m2 x 6 was thought to be an adequate dose. Seizure occurred in one patient, and conjunctivitis was seen in another. In conclusion, from the manageable myelosuppression observed, administration of 3.0 g/m2 x 6 of ara-C seemed to be an adequate dose.