Low-dose cytosine arabinoside (Ara-C) therapy in the myelodysplastic syndromes and acute myelogenous leukemia

Thirthy-six patients with refractory anemia with excess of blasts in transformation (RAEBt), or acute myelogenous leukemia (AML) after myelodysplastic syndrome, and twenty-four patients with 'de novo' AML were treated with cytosine arabinoside (Ara-C) in low dosage. The two groups of patients were comparable with respect to age, hemoglobin level, white cell and platelet counts. Ara-C was administered subcutaneously at a dose of 10 mg/m² every 12 hours for 21 days. Treatments were repeated every 2-3 months depending on marrow cellularity. Overall, 30% complete response and 48% partial response were observed. Neutropenia and thrombocytopenia were frequent complications. Median survival from the start of treatment was 7 months in both groups; at least 25% of patients survived more than 12 months. Survival appeared to be related to treatment response: patients achieving complete remission survived significantly longer than those who had partial remission.