Allogeneic bone marrow transplantation for chronic myeloid leukemia in childhood: a report from the Société Française de Greffe de Moelle et de Thérapie Cellulaire (SFGM-TC)

To determine the results of allogeneic hematopoietic stem cell (HSC) transplantation for chronic myelogenous leukemia (CML) at various stages of the disease in children, a retrospective analysis was carried out on the outcome of transplants performed on 76 children and teenagers with CML between 1982 and 1998. In all, 60 patients were transplanted from a matched sibling donor (MSD) and 16 from a matched unrelated donor (MUD). There was a higher incidence of acute graft-versus-host disease after MUD transplantation (P<10−3). The main cause of death was transplant-related toxicity in both groups. In MSD recipients, the probability of relapse at 5 years for patients transplanted in the first chronic phase was lower than in patients transplanted in the advanced phase (relative risk (rr)=5.90; 95% confidence interval (CI), 1.85–18.82, P<0.01). The estimated 5-year event-free survival (EFS) rate was higher after MSD vs MUD transplantation (61% (95% CI, 48–73%) vs 27% (95% CI, 4–49%), rr=0.25, P<10−3). In children transplanted from MSD, the 5-year EFS was higher when transplantation was performed in the first chronic phase vs the advanced phases (73% (95% CI, 59–87%) vs 32% (95% CI, 10–54%), P<10−3). Disease status at transplantation was the unique factor influencing survival in patients undergoing transplantation from MSD with a better outcome for those transplanted in the first chronic phase. Allogeneic HSC offers a possibility of curing childhood CML with a significant advantage for patients transplanted in chronic phase using a human leukocyte antigen-identical sibling donor.