[Using next generation sequencing technology to analyze gene mutations in patients with acute myeloid leukemia and...

Objective: To analyze the distribution of gene mutations in newly diagnosed acute myeloid leukemia (AML) patients, based on next generation sequencing technology (NGS) and to evaluate their value in AML risk stratification. Methods: The study analyzed 453 newly diagnosed AML(excluded acute promyelocytic leukemia, APL) patients from seven hospitals in Shanghai, from January 1st 2014 to December 31th 2017. RNA and DNA were extracted from pretreatment bone marrow mononuclear cells and targeted sequencing of AML genes were performed. The data of different groups was compared. Results: A total of 453 newly diagnosed AML patients were enrolled in the study, including 247 males and 206 females with a median age of 49.5 (range,11-85) years. A total of 540 mutations/fusion genes were detected in 289 patients, 29.1% (132/259) of whom with two or more mutations/fusion genes. In all patients, NPM1 was the most common mutation(12.8%), followed by ETO and TET2 mutation (11.92% and 11.04%, respectively) . And WT1 over-expression accounted for 10.6%. Patients over the age of 50 were with a higher frequency of mutations associated with epigenetic modification, 11.93% for ASXL1, 13.99% for DMNT3A, 6.58% for IDH1/IDH2, and 13.17% for TET2. The frequency of DMNT3A mutations was three times higher than that of patients under 50 years of age (P=0.017). In this study, a relatively low proportion of genetic mutations was observed in low-risk karyotype group. In the medium-risk karyotype group, the relatively high mutation frequencies were observed in NPM1, TET2, FLT3-ITD, DNMT3A, ASXL1, and CEBPA genes. In the poor-risk karyotype group, the mutation frequencies of ASXL1, TET2, DNMT3A and PHF6 genes were more than 10%, especially ASXL1 and PHF6 mutation frequencies were significantly higher than other molecular risk stratification groups (P<0.05). Of the 254 patients (56%) with normal karyotype AML (NK-AML), 56 patients were detected to have gene mutations about epigenetic modification. The median OS of this group was worse than that of patients without related mutations, while the median LFS had no significant difference. In patients with NK-AML older than 50 years, the OS and LFS of patients with epigenetic modification related gene mutations was 12 months and 10 months, versus 18 months and 12 months of patients without mutations. Conclusions: The gene mutations frequencies in AML patients with different age and molecular risk stratification groups are different. Epigenetics gene mutation frequencies, such as DNMT3A, ASXL1, IDH1/IDH2 and TET2,are higher in patients older than 50 years. A shorter OS can be observed in older patients(>50 years) with epigenetics gene mutation.