[Analysis of 7 cases of pediatric acute myeloid leukemia with DEK-NUP214 fusion gene].

To investigate the clinical features, treatment regime, and outcome of pediatric acute myeloid leukemia (AML) with DEK-NUP214 fusion gene. The clinical data, genetic and molecular results, treatment process and survival status of 7 cases of DEK-NUP214 fusion gene positive AML children admitted to the Pediatric Blood Diseases Center of Institute of Hematology & Blood Diseases Hospital, Chinese Academy of Medical Sciences from May 2015 to February 2022 were analyzed retrospectively. DEK-NUP214 fusion gene positive AML accounted for 1.02% (7/683) of pediatric AML diagnosed in the same period, with 4 males and 3 females. The age of disease onset was 8.2 (7.5, 9.5) years. The blast percentage in bone marrow was 0.275 (0.225, 0.480), and 6 cases were M5 by FAB classification. Pathological hematopoiesis was observed in all cases except for one whose bone marrow morphology was unknown. Three cases carried FLT3-ITD mutations, 4 cases carried NRAS mutations, and 2 cases carried KRAS mutations. After diagnosis, 4 cases received IAE induction regimen (idarubicin, cytarabine and etoposide), 1 case received MAE induction regimen (mitoxantrone, cytarabine and etoposide), 1 case received DAH induction regimen (daunorubicin, cytarabine and homoharringtonine) and 1 case received DAE induction regimen (daunorubicin, cytarabine and etoposide). Complete remission was achieved in 3 cases after one course of induction. Four cases who did not achieved complete remission received CAG (aclarubicin, cytarabine and granulocyte colony-stimulating factor), IAH (idarubicin, cytarabine and homoharringtonine), CAG combined with cladribine, and HAG (homoharringtonine, cytarabine and granulocyte colony-stimulating factor) combined with cladribine reinduction therapy, respectively, all 4 cases reached complete remission. Six patients received hematopoietic stem cell transplantation (HSCT) after 1-2 sessions of intensive consolidation treatment, except that one case was lost to follow-up after complete remission. The time from diagnosis to HSCT was 143 (121, 174) days. Before HSCT, one case was positive for flow cytometry minimal residual disease and 3 cases were positive for DEK-NUP214 fusion gene. Three cases accepted haploid donors, 2 cases accepted unrelated cord blood donors, and 1 case accepted matched sibling donor. The follow-up time was 20.4 (12.9, 53.1) months, the overall survival and event free survival rates were all 100%. Pediatric AML with DEK-NUP214 fusion gene is a unique and rare subtype, often diagnosed in relatively older children. The disease is characterized with a low blast percentage in bone marrow, significant pathological hematopoiesis and a high mutation rate in FLT3-ITD and RAS genes. Low remission rate by chemotherapy only and very high recurrence rate indicate its high malignancy and poor prognosis. Early HSCT after the first complete remission can improve its prognosis.