Prognostic impact of peripheral blood WT1- mRNA expression in patients with MDS

Few reports suggested a prognostic impact of Wilms‘ Tumor-1 ( WT1 )-mRNA overexpression in MDS, but translation into clinical routine was hampered by limited patients numbers, differing sample sources, non-standardized methods/cut-offs. To evaluate whether WT1- mRNA expression yields additional prognostic information, we measured peripheral blood (PB) WT1- mRNA expression in 94 MDS using a standardized assay offering a validated cut-off to discriminate between normal and WT1- mRNA overexpression. Overall, 54 patients (57%) showed WT1- mRNA overexpression, while 40 patients (43%) had normal WT1 -mRNA expression. This enabled discrimination between MDS and both healthy controls and non-MDS cytopenias. Furthermore, WT1- mRNA expression correlated with WHO 2016 subcategories and IPSS-R as indicated by mean WT1- mRNA expression and frequency of WT1 -mRNA overexpressing patients within respective subgroups. Regarding the entire group, PB WT1- mRNA expression was associated with prognosis, as those patients showing WT1- mRNA overexpression had higher risk for disease progression and AML transformation and accordingly shorter progression-free, leukemia-free and overall survival in univariate analysis. In multivariate analysis, prognostic impact of PB WT1- mRNA expression status was independent of IPSS-R and enabled more precise prediction of PFS, but not OS, within IPSS-R very low/low and intermediate risk groups. Overall, measuring PB WT1- mRNA appears valuable to support diagnostics and refine prognostication provided by the IPSS-R.