NRASmutDNMT3Amut Clone Identifies a Subset of de novo Cytogenetically Normal Acute Myeloid Leukemia with Adverse Prognosis.

OBJECTIVE: To investigate the molecular characteristics and clinical prognosis of the neuroblastoma RAS viral oncogene (NRAS) in patients with primary cytogenetically normal acute myeloid leukemia (AML). METHODS: A total of 171 adult patients with cytogenetically normal primary AML were collected, and 34 gene mutations in these patients were detected by targeted next-generation sequencing. RESULTS: Among 171 patients with cytogenetically normal AML(CN-AML), 17 (9.9%) patients had found NRAS mutations. Among the 17 NRAS mutant patients, 16 cases were associated with the concomitant gene, and NRAS mutation (NRASmut) was significantly positively correlated with DNMT3A mutation (DNMT3Amut) (P=0.011) and KRAS mutation (P=0.008) compared with the NRAS wild-type (NRASwt) group. The frequency of NRASmutDNMT3Amut clone was significantly higher in CN-AML patients with NRAS mutation (8/17, 47%). The total NRASmut group showed no significant differences on clinical characteristics, CR rate after induction therapy, OS, and RFS as compared with NRASwt group. However, patients with NRASmutDNMT3Amut provided a shorter effect on OS (median:7 vs 15 months; P=0.036) and RFS (median: 3 vs 12 months; P=0.003) than those with NRASwt, though no statistic differences on demographics, lab parameters, treatment and CR rate of patients receiving induction therapy. Multivariate analysis showed that NRASmutDNMT3Amut subtype could independently affect the RFS of CN-AML patients (HR:3.210, 95%CI:1.078-9.557, P=0.036). CONCLUSION: NRASmutDNMT3Amut clones have a high frequency of occurrence and show a poor survival prognosis. Our findings highlight potentially novel aspects of the underlying biology of NRASmutDNMT3Amut commutation in adult de novo CN-AML.

The impact of DNMT3A variant allele frequency and two different comutations on patients with de novo cytogenetically normal acute myeloid leukemia.

To refine the biological and prognostic significance of DNMT3A mutations in acute myeloid leukemia (AML), we assessed the impact of DNMT3A variant allele frequency (VAF) and its comutations in this study. Using targeted next-generation sequencing, we analyzed 171 adult patients with de novo cytogenetically normal AML for DNMT3A mutations and associated comutations. DNMT3Amut was detected in 35 patients. DNMT3Amut patients were divided into DNMT3AHigh and DNMT3ALow using a cut-off VAF value of 42%. We observed that DNMT3AHigh patients at diagnosis had increasing white blood cell (WBC) counts (p < 0.001) and a higher lactate dehydrogenase (LDH) level (p = 0.027), and were associated with lower complete remission (CR) rate (p = 0.015) and shorter overall survival (OS) (p = 0.032) than DNMT3ALow patients. We classified two different comutated genetypes, including DNMT3Amut NPM1mut FLT3-ITDmut and DNMT3Amut IDH1/IDH2mut . Patients with DNMT3Amut NPM1mut FLT3-ITDmut showed worse OS (p = 0.026) and relapse-free survival (RFS) (p = 0.003) than those with DNMT3Amut IDH1/IDH2mut , and showed a shorter OS (p = 0.027) than those with DNMT3Awt NPM1mut FLT3-ITDmut . We also observed that patients with DNMT3Amut IDH1/IDH2mut had higher platelet counts (p = 0.009) and a lower BM blast percentage (p = 0.040) than those with DNMT3Awt IDH1/IDH2mut . In multivariate analyses, DNMT3AHigh was independently associated with a lower CR rate (OR = 5.883; p = 0.004) and shorter OS (HR = 3.768; p < 0.001). DNMT3Amut NPM1mut FLT3-ITDmut independently affected worse OS (HR = 6.030; p < 0.001) and RFS (HR = 8.939; p < 0.001). Our findings might be potentially useful for predicting clinical outcomes.