Next-Frontiers in Precision Medicine: Genomic Profiling of Pediatric Acute Myeloid Leukemia in Brazil

Acute Myeloid Leukemia (AML) accounts for 10‒15% of pediatric acute leukemias and presents aggressive clinical behavior, with overall survival rates of 65‒70%. Diagnosis integrates morphological, immunophenotypic, cytogenetic, and molecular analyses, in which driver alterations guide prognosis and therapeutic decisions. However, the clinical translation of molecular findings remains constrained by the low frequency of actionable biomarkers, small cohorts, and the difficulty of integrating molecular profiling with Minimal Residual Disease (MRD) monitoring and outcomes. Moreover, alterations associated with a favorable prognosis may also be observed in relapsed cases, highlighting biological heterogeneity and a gap between molecular data and real-time clinical decision-making. Characterize genomic alterations in Brazilian pediatric AML patients and discuss translational challenges for precision medicine. This longitudinal cohort study (2018‒2025) included molecular analyses of bone marrow and peripheral blood samples and review of electronic medical records (follow-up ±7 years). Pediatric patients (=18 years) with confirmed AML were enrolled, with diagnostic support by multiparametric flow cytometry. Molecular profiling involved RT-PCR detection of recurrent fusion transcripts (RUNX1::RUNX1T1, PML::RARA, CBFB::MYH11, BCR::ABL1, and KMT2A rearrangements). FLT3 mutations (ITD and TKD) were assessed by fragment analysis, and NPM1 and CEBPA mutations by Sanger sequencing using genomic DNA and cDNA. The study was approved by the local Research Ethics Committee. Results: The study included 36 pediatric patients diagnosed with AML, evenly distributed between genders, boys (n= 18/36) and girls (n= 18/36), with a mean age of 9 years, all treated according to the BFM (n= 17/36) and GELMAI (n= 19/36) protocols. A comprehensive molecular profile was performed to characterize the main genetic alterations associated with the disease. Molecular markers defined by the European Leukemia Net (ELN) as eligible for molecular MRD monitoring were identified in 22.2% of patients (n= 8/36). The most prevalent genetic alterations were PML::RARA and RUNX1::RUNX1T1 fusions, each detected in 27.8% of cases (n= 10/36), followed by rearrangements involving CBFB::MYH11 and KMT2A at lower frequencies. Intermediate-frequency alterations included mutations in NPM1 and FLT3-TKD, identified either alone or in association with CBFB::MYH11 (5.6% each; n= 2/36). Less frequent events included FLT3-ITD with a low allelic ratio and the KMT2A::MLLT1 fusion, each identified in 5.6% of cases (n= 2/36). Molecular alterations involving FLT3, NPM1, and KMT2A rearrangements were predominantly observed among patients who experienced disease relapse or adverse outcomes, whereas patients harboring core-binding factor fusions more frequently achieved sustained remission. At the time of analysis, 63.9% of patients (n= 23/36) were in clinical remission, while 36.1% (n= 13/36) had died. The observed associations between molecular alterations and clinical patterns support the clinical relevance of integrated molecular profiling for prognostic assessment and therapeutic guidance in pediatric AML. At the same time, these findings highlight persistent challenges in translating molecular data into effective theranostic strategies in real-world clinical settings.