Long-Term Follow-up of Allogeneic Hematopoietic Stem Cell Transplantation for De Novo Acute Myelogenous Leukemia with a Conditioning Regimen of Total Body Irradiation and Granulocyte Colony-Stimulating Factor-Combined High-Dose Cytarabine

We retrospectively evaluated the efficacy and safety of total body irradiation (TBI) and granulocyte colony-stimulating factor (G-CSF)-combined high-dose cytarabine as a conditioning regimen for allogeneic hematopoietic stem cell transplantation (HSCT) in patients with de novo acute myelogenous leukemia (AML). The conditioning regimen consisted of 12 Gy of TBI followed by high-dose cytarabine (3 g/m²) every 12 hours for 4 days in combination with the continuous administration of G-CSF. Stem cell sources included bone marrow or peripheral blood stem cells (PBSC) from human leukocyte antigen (HLA)-identical siblings (n = 24), or bone marrow from HLA serologically matched unrelated donors (n = 26). Fifty patients (median age, 38 years) were evaluated. At HSCT, 35 patients were in the first or second complete remission (CR1/2), and 15 patients were not in remission (n = 14) or in the third CR (n = 1). Thirty-six of 50 patients are currently alive, with a median follow-up period of 5.6 years (range: 1.1-12.1 years). The 5-year estimated overall survival (OS) and disease-free survival (DFS) rates were 85.5% (95% confidence interval [CI], 73.7%-97.3%) and 82.1% (95% CI, 69.0%-95.2%) in patients with AML in the first or second CR, 46.7% (95% CI, 21.4%-72.0%), and 40.0% (95% CI, 15.3%-64.7%) in patients with AML in other stages. The 2-year cumulative incidence of treatment-related mortality (TRM) of all patients was 10.4% (95% CI, 1.8%-18.6%). The only factors affecting the OS and DFS were disease status at transplant and cytogenetics by multivariate analysis. These results suggest that G-CSF-combined high-dose cytarabine could be a promising component of the conditioning regimen for allogeneic HSCT for AML, providing a high DFS and low TRM.