WT1 Gene Expressions Predicting Posttransplant Outcome

Abstract 1499

Patients with AML show over expression of Wilms' tumor gene 1 (WT1). WT1 is a valuable prognostic parameter for minimal residual disease (MRD). Quantitation of this gene transcript by real-time quantitative PCR (RQ-PCR) may be useful for predicting prognosis in AML. We prospectively investigated the prognostic potential of the leukemia-associated antigen, WT1. We simultaneously determined the expression of the gene in bone marrow (BM) from 160 adult patients with newly diagnosed AML and healthy normal controls using RQ-PCR. The molecular profiles were then evaluated with multiple parameters. We evaluated whether the expression level of the gene in the patients affected complete remission (CR) and survival rates before and after hematopoietic stem cell transplant (HSCT). The median follow-up period for all patients who were event-free survivors was 30 months (range: 2–56). The Kaplan-Meier estimated overall survival (OS) and event-free survival (EFS) rates in the whole population of evaluable patients were 52% (95% CI, 31%–41%) and 50% (95% CI, 31%–43%), respectively. The median expression levels of the gene in normal control and patients were 7.4 (range 0.74–30.3), 58.6 (range 0.9–1950.5), respectively. Of note, WT1 levels of expression at initial diagnosis revealed influential to the EFS after HSCT (P =0.041). Interestingly, there were no correlated results with CR, OS, and EFS rates for treated AML, specifically before HSCT. This finding may suggest that initial expressions of WT1 possibly in association with the leukemic stem cells remained post-transplant can be the critical target of future immunotherapeutic trial.