EZH2 Mutations Are Related to Low Blast Percentage in Bone Marrow and -7/del(7q) in De Novo Acute Myeloid Leukemia

<div><p>The purpose of the present work was to determine the incidence and clinical implications of somatic EZH2 mutations in 714 patients with de novo acute myelogenous leukemia by sequencing the entire coding region. EZH2 mutations were identified in 13/714 (1.8%) of AML patients were found to be more common in males (<i>P</i> = 0.033). The presence of EZH2 mutations was significantly associated with lower blast percentage (21–30%) in bone marrow (<i>P</i><0.0001) and -7/del(7q) (<i>P</i> = 0.025). There were no differences in the incidence of mutation in 13 genes, ASXL1, CBL, c-KIT, DNMT3A, FLT3, IDH1, IDH2, MLL, NPM1, NRAS, RUNX1, TET2, and WT1, between patients with and without EZH2 mutations. No difference in complete remission, event-free survival, or overall survival was observed between patients with and without EZH2 mutation (<i>P</i>>0.05). Overall, these results showed EZH2 mutation in de novo acute myeloid leukemia as a recurrent genetic abnormality to be associated with lower blast percentage in BM and -7/del(7q).</p></div

Kaplan-Meier survival curves according to EZH2 mutation status.

<p>(A) EFS in de novo AML patients according to EZH2 mutations. The green line represents patients with mutated EZH2 (n = 12); and magenta line, patients with unmutated EZH2 (n = 277; <i>P</i> = 0.2283); (B) OS in de novo AML patients according to EZH2 mutations. The green line represents patients with mutated EZH2 (n = 12); and the magenta line represents patients with unmutated EZH2 (n = 277; P = 0.5001).</p

Comparison of clinical and laboratory features between AML patients with and without EZH2 mutation.

ψ<p>Risk status: Better-risk: inv(16)/t(16;16), t(8;21),t(15;17); Intermediate-risk: normal, +8, t(9;11), other undefined risk; Poor-risk: complex, −5, 5q−, −7, 7q−, 11q23(non t(9;11)), inv(3), t(3;3), t(6;9), t(9;22).</p><p>(A) Structure of the EZH2 protein and location of EZH2 mutations. (B) DNA sequencing chromatograms of AML genomic DNA samples showing 14 mutations in 13 AML patients.</p