Allogeneic Stem Cell Transplantation Can Be an Effective Post-Remission Strategy for Acute Myeloid Leukemia Patients Aged Less Than 60 Years with Core Binding Factor: A Nation-Wide Retrospective Study in Korea.

High-dose cytarabine (HDAC)-based postremission therapy has been generally considered to be more beneficial than allogeneic stem cell transplantation (alloSCT) for AML patients with core binding factor (CBF). However, advancements in methods and supportive care in SCT over decades have led to gradual improvement in the treatment-related mortality rate after alloSCT. Therefore, it could be considered that alloSCT after the first CR in AML with CBF patients may show better results than HDAC chemotherapy alone compared with past. We conducted a retrospective study in 169 patients with CBF AML aged less than 60 years collected in 18 institutions in Korea between 1994 and 2006, with comparing alloSCT (n= 60), autoSCT (n= 31) and HDAC chemotherapy (n= 78) as postremission therapy during first remission. With a median follow-up of 46 months, the probability of disease-free survival (DFS) and overall survival (OS) rates at 5 years were 67.8% and 66.6%, retrospectively. AlloSCT (83.1% ± 5.2%) shows a significantly improved 5-year probability of DFS over autoSCT (59.9% ± 9.6%) or HDAC (60.8% ± 6.2%; p=0.048). There was no differences in 5-year probability of OS from complete remission (CR) between 3 treatment arms. In comparison of DFS and OS according to period of enrollment of patients, 4-year probability of DFS or OS of the three groups prior to 2003 was not different, nonetheless, after 2003, 4-year probability of DFS was better in the group underwent alloSCT in comparison with the group without performing it (86.8% vs 70.0%; p=0.035), and in the group underwent SCT (alloSCT plus autoSCT) in comparison with the group without performing it (89.0% vs 67.3%; p=0.047). 4-year probability of OS has a tendency to be improved slightly in the group underwent SCT than the group without performing it (89.0% vs 67.3%; p=0.08). In comparison with prior to 2003, cumulative treatment-related mortality and relapse risk of alloSCT after 2003 was decreased to 13.5% vs 6.7% and 26.2% vs 6.9%, respectively, and depending on the result, 4-year probability of DFS and OS of the alloSCT showed the improvement from 73.9% and 63.3% prior to 2003 to 93.1% and 90.0% after 2003, respectively. This study has the limitation of retrospective study, nonetheless, it could suggest the possibility that alloSCT as a postremission therapy in AML with CBF patients after the first CR may be appropriate if a HLA matched sibling donor were available.