Assessing the impact of the 2017 European LeukemiaNet recommendations on FLT3 allelic ratio calculation and reporting in acute myeloid leukaemia

Recommendations for laboratory testing of UK patients with acute myeloid leukaemia

“…Internal tandem duplications (ITD) and tyrosine kinase domain (TKD) driver variants in FLT3 have been shown to respond to FLT3 inhibitors and as such their rapid identification is critical. Although the FLT3 ‐ITD allelic ratio (AR) is no longer required for assignment of ELN risk group, it is recommended that this is still reported if the assay is appropriately standardised and validated for this purpose, 29 as AR provides additional prognostic information which may be valuable in some situations. Whilst rapid identification of the recurrent driver variants in exon 11 of NPM1 is not mandated, in practice they are often identified in tandem with FLT3 analyses for prognostic purposes and can also aid interpretation of cases of suspected APL without PML::RARA rearrangement as well as cases with morphological evidence of dysplasia 25 …”

Applicability of 2022 classifications of acute myeloid leukemia in the real-world setting

“…The accuracy of ELN 2022 in identifying favorable-risk AML was confirmed with the use of our real-word data, with the clinical consequence of avoiding the overtreatment of patients. However, capillary electrophoresis continues to be recommended as the standardized diagnostic tool for FLT3 mutations, 30 particularly for its quick turnaround and in light of the indication for treatment with FLT3-inhibitors such as midostaurin as well as for its ability to detect longer size FLT3 -ITDs, which are underestimated in NGS. 31 …”