RUNX1 mutations in acute myeloid leukemia: Results from a comprehensive genetic and clinical analysis from the AML study group

Purpose: To evaluate frequency, biologic features, and clinical relevance of RUNX1 mutations in acute myeloid leukemia (AML) Patients and Methods: Diagnostic samples from 945 patients (age 18 to 60 years) were analyzed for RUNX1 mutations. In a subset of cases (n = 269), microarray gene expression analysis was performed Results: Fifty-nine RUNX1 mutations were identified in 53 (5.6%) of 945 cases, predominantly in exons 3 (n = 11), 4 (n = 10), and 8 (n = 23). RUNX1 mutations clustered in the intermediate-risk cytogenetic group (46 of 640, 7.2%; cytogenetically normal, 34 of 538, 6.3%), whereas they were less frequent in adverse-risk cytogenetics (five of 109, 4.6%) and absent in core-binding-factor AML (0 of 77) and acute promyelocytic leukemia (0 of 61). RUNX1 mutations were associated with MLL-partial tandem duplications (P =.0007) and IDH1/IDH2 mutations (P =.03), inversely correlated with NPM1 (P <.0001), and in trend with CEBPA (P =.10) mutations. RUNX1 mutations were characterized by a distinct gene expression pattern; this RUNX1 mutation-derived signature was not exclusive for the mutation, but also included mostly adverse-risk AML [eg, 7q-,-7, inv(3), ort(3;3)]. RUNX1 mutations predicted for resistance to chemotherapy (rates of refractory disease 30% and 19%, P =.047, for RUNX1-mutated and wild-type patients, respectively), as well as inferior event-free survival (EFS; P <.0001), relapse-free survival (RFS, P =.022), and overall survival (P =.051). In multivariable analysis, RUNX1 mutations were an independent prognostic marker for shorter EFS (P =.007). Explorative subgroup analysis revealed that allogeneic hematopoietic stem-cel transplantation had a favorable impact on RFS in RUNX1-mutated patients (P <.0001) Conclusion: AML with RUNX1 mutations are characterized by distinct genetic properties and are associated with resistance to therapy and inferior outcome