On the basis of age ( median , @ years ; range , @ to @ years ) , performance status , WBC count , and mutation status of NPM@ , CEBPA , and FLT@-internal tandem duplication , patients were classified into the following three risk groups according to PINAOS and PINARFS : @ % of all patients and @ % of @ responding patients had low-risk disease ( @-year OS , @ % ; @-year RFS , @ % ) ; @ % of all patients and @ % of responding patients had intermediate-risk disease ( @-year OS , @ % ; @-year RFS , @ % ) , and @ % of all patients and @ % of responding patients had high-risk disease ( @-year OS , @ % ; @-year RFS , @ % ) , respectively .