The Characteristics and Outcomes of Adult Acute Myeloid Leukemia Patients With KMT2A-Partial Tandem Duplication.

Introduction: KMT2A-Partial Tandem Duplication (KMT2A-PTD) is a recurrent gene mutation present in acute myeloid leukemia (AML) and its prognostic significance needs to be clarified.

Methods: Three hundred and eighty-seven consecutive adult newly diagnosed AML patients with non-favorable cytogenetic risk were tested for KMT2A-PTD by real-time quantitative PCR. All patients were screened for AML-related gene fusions and mutations.

Results: Thirty-two (8.3%) patients were identified as KMT2A-PTD (+). KMT2A-PTD significantly co-occurred with FLT3-ITD, RUNX1, and DNMT3A mutation and tended to be related to normal karyotype (p < 0.0001, p = 0.0001, 0.019, and 0.062). Furthermore, none of the KMT2A-PTD (+) patients had NPM1 mutation, CEBPA bZIP in-frame mutation (p = 0.0005 and 0.0009), and none of them had KMT2A-rearrangement and other gene fusions (p = 0.16). As a result, all KMT2A-PTD (+) patients were categorized into ELN2022-intermediate or adverse groups (p < 0.0001). KMT2A-PTD was not related to patients' age, sex, white blood cell (WBC) counts, hemoglobin (Hb) level, platelet (PLT) counts, percentage of bone marrow blast cells, and FAB subtypes (all p > 0.05). KMT2A-PTD had no effect on complete remission achievement after 1 and 2 courses of induction therapy, relapse-free survival, and overall survival in both the entire cohort and within the following five subgroups: FLT3-ITD (+), RUNX1 mutation, DNMT3A mutation, ELN2022-intermediate, and ELN2022-adverse categories, respectively (all p > 0.05). Moreover, KMT2A-PTD (+) patients also could not be stratified by them (all p > 0.05).

Conclusion: KMT2A-PTD harbored its distinct genetic characteristics and had no prognostic impacts in AML.