An effective chemotherapeutic regimen for acute myeloid leukemia and myelodysplastic syndrome in children with Down's syndrome

In recent pediatric collaborative studies of acute myeloid leukemia (AML), patients with Down's syndrome (DS) have better outcome than other patients when they were treated according to their intensive AML protocols. This may be attributed to enhanced sensitivity of DS AML cells to selected chemothe rapeutic agents. We evaluated a less intensive chemotherapeutic regimen whi ch was specifically designed for children with AML-DS. Remission induction chemotherapy consisted of daunorubicin (25 mg/m(2)/day for 2 days), cytosin e arabinoside (100 mg/m(2)/day for 7 days), and etoposide (150 mg/m(2)/day for 3 days). Patients received one to seven courses of consolidation therap y of the same regimen. Thirty-three patients were enrolled on the study and their clinical, hematologic and immunophenotypic features were analyzed. O f the 33 patients, all were younger than 4 years and diagnosed as having ac ute megakaryoblastic leukemia or myelodysplastic syndrome. All patients ach ieved a complete remission and estimated 8 year event-free survival rate wa s 80 +/- 7%. Three patients relapsed and two died due to cardiac toxicity a nd one due to septic shock. The results of our study showed that patients w ith AML-DS constitute a unique biologic subgroup and should be treated acco rding to a less intensive protocol designed for AML-DS.