Prospective study of a pirarubicin, intermediate-dose cytarabine, and etoposide regimen in children with Down syndrome and acute myeloid leukemia: the Japanese Childhood AML Cooperative Study Group.

Purpose: To evaluate a less intensive chemotherapeutic regimen specifically designed for patients with Down syndrome (DS) and acute myeloid leukemia (AML), and to determine the prognostic factors for event-free survival.

Patients And Methods: Seventy-two patients with AML-DS were treated with remission induction chemotherapy consisting of pirarubicin (25 mg/m2/d for 2 days), cytarabine (100 mg/m2/d for 7 days), and etoposide (150 mg/m2/d for 3 days). Patients received four courses of intensification therapy of the same regimen. Prophylaxis for CNS leukemia was not included.

Results: All but two patients were younger than 4 years, and 67 of the 72 patients (93%) were diagnosed as acute megakaryoblastic leukemia (AMKL). Seventy of the 72 patients (97.2%) achieved a complete remission (CR), and the estimated 4-year event-free survival (EFS) rate was 83% +/- 9%. Nine patients relapsed, and one died as a result of pneumonia during CR. Multivariate analysis revealed that the presence of monosomy 7 was a greater risk factor of adverse outcome (odds ratio = 5.67; P = .027).

Conclusion: A less intensive chemotherapeutic regimen produces excellent outcomes in standard-risk AML-DS patient. Risk-oriented therapy should be considered for future trials in AML-DS.