Long-term results of an ultra low-dose cytarabine-based regimen for the treatment of acute megakaryoblastic leukaemia in children with Down syndrome.

Children with acute megakaryoblastic leukaemia (AMKL) and Down syndrome (DS) show a favourable response to chemotherapy, probably due to increased sensitivity of the leukaemic blasts to cytarabine. In contrast, dose-intensive approaches have resulted in disproportionate treatment-related mortality in this group. The survival of children with AMKL and DS was retrospectively compared following treatment with a low-dose chemotherapy protocol, consisting of cytarabine (10 mg/m2/dose), retinylpalmitate and vincristine or standard chemotherapy. Event-free (67 +/- 11%) and overall survival (77 +/- 10%) at 5 years were not significantly different in both groups. Further reduction of treatment intensity in AMKL of children with DS, therefore, appears feasible.