IDH1 and IDH2 mutations confer an adverse effect in patients with acute myeloid leukemia lacking the NPM1 mutation

We examined the incidence and prognostic effect of IDH1 and IDH2 mutations in 233 Japanese adults with acute myeloid leukemia (AML). IDH1 R132 mutations were detected in 20 (8.6%) patients with AML. IDH2 mutations were found in 19 (8.2%, 17 R140 and two R172) patients. IDH1 and IDH2 mutations were mutually exclusive and were associated with normal karyotype AML, cytogenetic intermediate-risk group, and NPM1 mutations. Five-year overall survival (OS) rates were significantly lower (15.6%) in patients harboring the IDH mutations than in patients lacking the IDH mutation (32.0%) in the entire cohort of AML (P=0.005). Among patients aged 59yr or younger with IDH mutations, 5-yr OS in patients who underwent allogeneic stem cell transplantation (SCT) was significantly higher than that in those not receiving allogeneic SCT (50% vs. 10.6%, P=0.020). Of 51 patients with NPM1 mutations, there was no significant difference in 5-yr OS rates between patients with and those without the IDH mutations. In contrast, among 175 patients lacking the NPM1 mutations, 5-yr OS rate in patients with IDH mutations was significantly lower than that in those without IDH mutations (0% vs. 34.7%, P=<0.001). These data suggest that IDH mutations have an unfavorable effect in AML, especially AML with the NPM1 wild type and younger AML patients with IDH mutations may benefit from allogeneic SCT.