Gene mutation patterns in patients with minimally differentiated acute myeloid leukemia.

Minimally differentiated acute myeloid leukemia (AML-M0) is a rare subtype of AML with poor prognosis. Although genetic alterations are increasingly reported in AML, the gene mutations have not been comprehensively studied in AML-M0. We aimed to examine a wide spectrum of gene mutations in patients with AML-M0 to determine their clinical relevance. Twenty gene mutations including class I, class II, class III of epigenetic regulators (IDH1, IDH2, TET2, DNMT3A, MLL-PTD, ASXL1, and EZH2), and class IV (tumor suppressor genes) were analyzed in 67 patients with AML-M0. Mutational analysis was performed with polymerase chain reaction-based assays followed by direct sequencing. The most frequent gene mutations from our data were FLT3-ITD/FLT3-TKD (28.4%), followed by mutations in IDH1/IDH2 (28.8%), RUNX1 (23.9%), N-RAS/K-RAS (12.3%), TET2 (8.2%), DNMT3A (8.1%), MLL-PTD (7.8%), and ASXL1 (6.3%). Seventy-nine percent (53/67) of patients had at least one gene mutation. Class I genes (49.3%) were the most common mutated genes, which were mutually exclusive. Class III genes of epigenetic regulators were also frequent (43.9%). In multivariate analysis, old age [hazard ratio (HR) 1.029, 95% confidence interval (CI) 1.013-1.044, P=.001) was the independent adverse factor for overall survival, and RUNX1 mutation (HR 2.326, 95% CI 0.978-5.533, P=.056) had a trend toward inferior survival. In conclusion, our study showed a high frequency of FLT3, RUNX1, and IDH mutations in AML-M0, suggesting that these mutations played a role in the pathogenesis and served as potential therapeutic targets in this rare and unfavorable subtype of AML.