Outcome of Childhood Acute Myeloid Leukemia With FLT3-ITD Mutation: The Experience of Children’s Cancer Hospital Egypt, 2007-17

The presence of FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutation in pediatric acute myeloid leukemia (AML) is associated with high rates of induction failure and worse survival. Its presence places the patient into a high-risk group. We aimed to describe the outcome of pediatric AML with FLT3-ITD mutation. We performed a retrospective analysis of cases of AML from July 2007 till July 2017 at Children’s Cancer Hospital Egypt. Seventy-one patients had FLT3 gene mutation out of 687 patients with AML. Sixty-five patients had FLT3 gene mutation with allelic ratio > 0.4; 43 (66.1%) of 65 patients experienced complete remission (CR). Of the 43 patients, 16 patients maintained CR, 18 patients relapsed after first CR, 8 patients died, and 1 patient was lost to follow-up. Patients with relapsing disease died after salvage chemotherapy, except for one patient, who was alive after second CR. Allogeneic bone marrow transplantation (allo-BMT) was performed for 9 (13.8%) of 65 patients in first CR, of whom 8 were alive and in CR, and 1 patient experienced disease relapse and died. Seven patients (10.7%) were alive without allo-BMT. Three years’ overall and event-free survival for patients with FLT3-ITD mutation with high allelic ratio was 26.9% and 22.8%, respectively. Three years’ overall and event-free survival for patients treated with allo-BMT was 77.8% and 78.8%, respectively, versus patients treated without allo-BMT, 16.3% and 12.8%, respectively. FLT3-ITD mutation in pediatric AML was associated with poor treatment outcomes, and the survival of relapsing patients was extremely poor. Allo-BMT in first remission was the best treatment option. Alternative donor transplants and FLT3 inhibitors are needed to improve outcome in developing countries. In an analysis of the outcome of pediatric acute myeloid leukemia (AML) with FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutation over 10 years at Children’s Cancer Hospital Egypt, we found that FLT3-ITD mutation was associated with poor outcomes, and survival of patients who experienced relapse was extremely poor. Allogeneic bone marrow transplantation while the patient is experiencing first remission was the best treatment option. FLT3 inhibitors are needed to improve the outcome in AML in developing countries.