Autologous stem cell transplantation for advanced acute myeloid leukemia

We studied the efficacy of a two-step approach to autologous stem cell transplantation for patients with advanced acute myeloid leukemia. Step 1 consisted of consolidation chemotherapy using cytarabine 2000 mg/m2 twice daily for 4 days plus etoposide 40 mg/kg by continuous infusion over the same 4 days. Peripheral blood stem cells were collected under granulocyte colony-stimulating factor (G-CSF) stimulation during recovery from this chemotherapy. Step 2, autologous stem cell transplantation, utilized the preparative regimen of oral busulfan 16 mg/kg followed by etoposide 60 mg/kg i.v. During step 1, there were no treatment-related deaths among 28 patients, but two patients did not proceed to transplantation because of failure of mobilization. A median CD34+ dose (×106/kg) of 13.6 was collected. Of 26 patients undergoing autologous transplant, there was one treatment-related death and 12 relapses. With a median follow-up of 5.4 years, 5 year event-free survival (EFS) of all patients entered is 54%. The most important prognostic factor was cytogenetic changes. All seven patients with t(15,17) remained in long-term remission whereas EFS for other patients was 38%. We conclude that this two-step approach to autologous transplantation produces excellent stem cell yields, allows a high percentage of patients to receive the intended therapy, and provides effective treatment.