[Research on the clinical characteristics and prognosis of children with chronic myeloid leukemia in the blast phase].

<b>Objective:</b> To explore the clinical characteristics and prognosis of children with chronic myeloid leukemia in the blast phase (CML-BP) . <b>Methods:</b> The clinical characteristics, treatment measures, and survival outcomes of 28 children with CML-BP were analyzed in our hospital from January 2008 to November 2022. <b>Results:</b> The male to female ratio of the 28 children with CML-BP was 1.15∶1. The median age of diagnosis of CML-BP was 10 years, and the median follow-up time was 79 months. During the diagnosis of CML, four children were in the BP, one was in the accelerated phase (AP) and 23 children were in the chronic phase (CP). Among the 23 children with CML-CP, 75% had progressed directly from CP to BP without experiencing the AP. Among the children diagnosed with CML-BP, 71.4% were classified as chronic myeloid leukemia lymphoid blast phase (CML-LBP), 25.0% belonged to the chronic myeloid leukemia myeloid blast phase (CML-MBP), and 3.6% belonged to the chronic myeloid leukemia mixed phenotype acute leukemia (CML-MPAL). Treatment with hemaopoietic stem cell transplantation (HSCT) after tyosine kinase inhibitor (TKI) combined with chemotherapy was administered to 19 children, two children received HSCT after TKI alone, and seven children received TKI combined with chemotherapy but without HSCT. The 5-year overall survival of the 28 children with CML-BP was 59.3%. <b>Conclusion:</b> The direct progression of BP from CP is greater in children with CML-BP compared with adults, and the overall prognosis of children with CML-BP is poor.