Clinical characteristics and prognostic significance of extramedullary involvement in childhood acute myeloid leukemia

Background . Extramedullary infiltration (EI) is relatively common in children with acute myeloid leukemia (AML) (up to 20-25 %). However, its clinical and prognostic significance remains poorly understood. Objective : describe features define of EI AML. Materials methods The subjects retrospective observational study were 228 de novo median age was 6.6 years. All them treated according the protocol AML-MM-2006 from April 2007 June 2018. patients divided into three cohorts localization lesions: 1) central nervous system (CNS) involvement (CNS group), 2) other localizations apart CNS (myelosarcomas (MS) 3) combined lesions + MS group). Results diagnosed 84 (36.84 %) Among 47 (55.95 had involvement, 20 (23.81 MS, 15 (17.86 both MS. 5-year overall survival (OS) rate slightly higher than without - 80 ± 12 % vs 71 9 %, p = 0.26, however OS significantly lower 45 16 <0.001. In addition, high-risk who underwent allogenic hematopoietic stem cell transplantation (HSCT) (± involvement) similar main groups 81 11 42 26 respectively, 0.004. event-free also 38 51 8 0.011. Conclusion Patients worse EFS our study. Moreover HSCT conducted first remission did not improve rate. Neuroleukemia as only an unfavorable factor cohort AML more often associated inv(16).