Objectives: Hypocellular acute myeloid leukemia (AML) is uncommon. Despite the prognostic and therapeutic importance of mutational analysis, the mutational landscape of hypocellular AML is not well understood.
Methods: We identified 25 patients with hypocellular AML, and 141 patients with nonhypocellular AML were identified as a control group. We applied next-generation sequencing for the first time to profile this entity.
Results: The hypocellular AML patients were older than those with nonhypocellular AML (P = .037). At diagnosis, hypocellular AML had lower leukocyte counts (P = .012), higher hemoglobin (P = .003), and lower blast counts in the peripheral blood (P < .001) and bone marrow (P = .003). Hypocellular AML was less likely to have mutations involving cell proliferation (P = .027) and NPM1 (P = .022) compared with nonhypocellular AML. Hypocellular AML showed a high incidence of spliceosomal mutations and myelodysplastic syndrome-defining chromosome abnormalities (65%), but the incidence was not significantly different from that in nonhypocellular AML. There was no significant survival difference between hypocellular and nonhypocellular AML.
Conclusions: To our knowledge, this study is the first to demonstrate hypocellular AML showed fewer genetic alterations involving cell proliferation and NPM1 when compared directly with nonhypocellular AML; this finding likely contributes to the low marrow cellularity in at least a portion of the patients with hypocellular AML.
Keywords: NPM1; Acute myeloid leukemia; Cell proliferation; Hypocellular; Mutation.
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