Impact of FLT3ITD mutant allele level on relapse risk in intermediate-risk acute myeloid leukemia

摘要

Some studies have suggested that cases of acute myeloid leukemia (AML) with low levels of FLT3 internal tandem duplications (FLT3ITD) do not have a worse prognosis if there is a concomitant NPM1 mutation, although this is controversial. To clarify this therapeutically important issue, we have analyzed FLT3ITD and NPM1MUT levels in 1609 younger adult cases of cytogenetically intermediate-risk AML.The cumulative incidence of relapse was increased in NPM1MUT cases by the presence of a FLT3 ITD, but did not differ markedly according to FLT3ITD level. This remained true when allowance was made for poor leukemic cell purity by adjustment of the FLT3ITD level to the measured NPM1MUT level. If consolidation therapies are to be determined by relapse risk, then NPM1MUT cases with low-level FLT3ITD should not be considered as good risk without further studies. AML 12 and AML 15 are registered at http://www.controlled-trials.com under ISRCTN17833622 and ISRCTN17161961, respectively.