Treatment of primary acute myeloid leukemia: results of a prospective multicenter trial including high-dose cytarabine or stem cell transplantation as post-remission strategy.

Background and Objectives: To evaluate a regimen of induction and consolidation chemotherapy, followed by a post-remission therapy which depended on age and cytogenetics, in patients with primary acute myeloid leukemia.
Design and Methods: Two hundred patients up to 60 years old received idarubicin, standard dose cytarabine and etoposide as induction chemotherapy and one consolidation course including intermediate dose cytarabine and mitoxantrone. Subsequently, patients with favorable cytogenetics, [i.e., t(8;21), inv(16)] were scheduled to receive 2 courses of high-dose cytarabine. The remainder were scheduled for allogeneic stem cell transplantation (SCT), if <or= 50 years old and with an HLA-identical sibling, or autologous SCT if >50 years old or lacking a donor.
Results: In patients with favorable cytogenetics the 4-year probabilities of survival and leukemia-free survival (LFS) were 62+/-9% and 41+/-10%, respectively. The results were better in patients with t(8;21). LFS at 4 years in patients <or= 50 years old allocated to allogeneic SCT was 41+/-9% vs 48+/-8% after autologous SCT (p=0.22). Patients >50 years old assigned to auto-SCT had a 4-year LFS of 17+/-9%. Adverse cytogenetics and white blood cell count >or= 20 yen 109/L at diagnosis were associated with lower probability of survival and leukemia-free survival.
Interpretation and Conclusions: We confirmed that high-dose cytarabine seems a good option for patients with t(8;21). Autologous and allogeneic SCT led to similar leukemia-free survival in patients <or= 50 years of age. In older patients, the results of auto-SCT were poor. Finally, cytogenetics and white cell count at diagnosis, together with new prognostic markers, should be considered in the design of future risk-adapted trials.