MECOM-Rearranged Acute Myeloid Leukemia: Pathobiology and Management Strategies

Acute myeloid leukemia (AML) is an aggressive clonal hematopoietic malignancy, characterized by marked biological heterogeneity and variable clinical outcomes. Among its rarer genetic subsets is AML with rearrangements of the MDS1 and EVI1 complex locus (MECOM), occurring in fewer than 2% of newly diagnosed cases. This review examines the biology and clinical significance of MECOM-rearranged AML, with a focus on its diverse mechanisms of leukemogenesis, including chromosomal inversion and translocation involving 3q26. We discuss how aberrant EVI1/MECOM activity alters gene expression networks and drives malignant transformation. Current therapeutic approaches-including intensive chemotherapy, hypomethylating agents in combination with venetoclax, and allogeneic stem cell transplantation-are evaluated with particular emphasis on inv(3) and other t(3q26) subtypes. Despite these treatment strategies, outcomes remain poor, underscoring the urgent need for novel, more effective therapies for this high-risk form of AML.