Outcome of children with high-risk acute myeloid leukemia given autologous or allogeneic hematopoietic cell transplantation in the aieop AML-2002/01 study

We analyzed the outcome of 243 children with high-risk (HR) AML in first CR1 enrolled in the AIEOP-2002/01 protocol, who were given either allogeneic (ALLO; n=141) or autologous (AUTO; n=102) hematopoietic SCT (HSCT), depending on the availability of a HLA-compatible sibling. Infants, patients with AML-M7, or complex karyotype or those with FLT3-ITD, were eligible to be transplanted also from alternative donors. All patients received a myeloablative regimen combining busulfan, cyclophosphamide and melphalan; [corrected] AUTO-HSCT patients received BM cells in most cases, while in children given ALLO-HSCT stem cell source was BM in 96, peripheral blood in 19 and cord blood in 26. With a median follow-up of 57 months (range 12-130), the probability of disease-free survival (DFS) was 73% and 63% in patients given either ALLO- or AUTO-HSCT, respectively (P=NS). Although the cumulative incidence (CI) of relapse was lower in ALLO- than in AUTO-HSCT recipients (17% vs 28%, respectively; P=0.043), the CI of TRM was 7% in both groups. Patients transplanted with unrelated donor cord blood had a remarkable 92.3% 8-year DFS probability. Altogether, these data confirm that HSCT is a suitable option for preventing leukemia recurrence in HR children with CR1 AML.