Anaiysis Of Clinical Features And Prognosis In Pediatric Patients With Acute Megakaryocytic Leukemia

Objective: To explore the clinical manifestation,efficacy and prognosis of children with acute megakaryocytic leukemia(AMKL)treated by AML03 protocol.Methods: We report the clinical data of 47 pediatric patients with de novo AMKL from May 2011 to December 2019,22 patients of which without Down Syndrome(DS)enrolled in study AML03.Treatment effect and prognostic factors of 22 non-DS-AMKL patients were retrospectively analyzed.SPSS25.0 was used for statistical analysis,Kaplan-Meier survival analysis was established to analyze the prognostic factors.Results: 23 patients did not treat,and the median follow-up time of the remaining 24 patients was 10.3 months.Among them,two patients were DS-AMKL patients treated by DS-AML protocol,and 22 non-DS-AMKL patients received 4 courses of chemotherapy or allogeneic hematopoietic stem cell transplant(allo-HSCT)after complete remission(CR)with 1-3 courses of chemotherapy.Among the 22 non-DSAMKL patients,after induction I and induction II,the CR rates of bone marrow cytology were 70.0% and 85.0%,and the minimal resident disease(MRD)negative rates were 41.2% and 78.9% respectively.The 2-year OS and 2-year EFS of 22 non-DS-AMKL patients were 52.9%±12.7% and 40.1%±12.8% respectively.Six patients relapsed with an accumulative recurrence rate of 27.3%,and eight patients died with an accumulative mortality rate of 36.4%.Univariate analysis suggested that uncomplete remission of bone marrow cytology and positive MRD after induction II were risk factors for EFS and OS.The immunophenotypic markers of CD56 positive are risk factors for EFS and OS.There was no significant difference in 2-year OS and 2-year EFS between chemotherapy alone and allo-HSCT.Conclusion: AMKL is a highly heterogeneous disease with a poor prognosis compared to other AML subgroups.The survival rate of non-DS-AMKL treated by AML03 protocol approached advanced international level.Immunophenotype,bone marrow cytology and MRD after induction II were important factors affecting the longterm prognosis,and allo-HSCT did not significantly improve in the prognosis compared to chemotherapy alone.