Excellent outcomes of children with CML treated with imatinib mesylate compared to that in pre-imatinib era.

Allogeneic hematopoietic stem cell transplantation (HSCT) and tyrosine kinase inhibitor have revolutionized the treatment of patients with chronic myeloid leukemia (CML). In this study, the clinical impact of HSCT and imatinib mesylate (IM) was retrospectively analyzed in 28 children with CML treated in our institutes from 1984 to 2008. Twelve patients were given oral IM. At 36 months after initiation of IM therapy, the complete cytogenetic response rate was 90.9%, and the major molecular response rate was 36.4%. Sixteen children received allogeneic HSCT without administration of IM. The stage of disease at transplantation was: first chronic phase (n = 10), second chronic phase (n = 2), accelerated phase (n = 2), and blastic crisis (n = 2). The progression rate was significantly lower in patients treated with IM than in those treated without IM (0 vs. 28.6%, p = 0.006). In summary, the survival outcomes of pediatric patients with CML were dramatically improved by treatment with IM compared to HSCT.