Non-TBI Hematopoietic Stem Cell Transplantation in Pediatric AML Patients: A Single-center Experience

Background: Hematopoietic stem cell transplantation (HSCT) has been established as a promising treatment in acute myeloid leukaemia (AML). Several studies have been performed to minimize the toxicity of HSCT in children without impairing the efficacy. We report our long-term results of HSCT in pediatric AML patients using non-total body irradiation conditioning regimen.Procedure: From May 1991 to June 2010, 133 pediatric patients with AML (age<15 y) who were referred to our institute underwent autologous (auto-) or allogeneic (allo-) HSCT. The conditioning regimen consisted of oral busulfan plus etoposide in auto-HSCT patients and oral busulfan plus cyclophosphamide in allo-HSCT patients.Results: Overall survival (OS), leukemia-free survival (LFS), probability of relapse, and transplantation-related mortality at 3 years were 67.6%, 62.2.5%, 27.3%, and 10.1%, respectively. There was no significant difference between allo-HSCT and auto-HSCT groups. In multivariable analysis using Cox proportional hazards regression model, male sex was associated with significantly improved OS (P<0.001) and LFS (P=0.022). An age 3 years was associated with higher relapse (P=0.034) and worse OS (P=0.001) and LFS (P=0.014).Conclusions: The role of allo-HSCT in pediatric AML patients in first complete remission is uncertain. Further randomized studies are recommended to clarify the optimal postremission therapy in these patients.