Prognostic significance of WT1 expression at diagnosis and end of induction in Egyptian adult acute myeloid leukemia patients.

BACKGROUND: Wilms' tumor (WT1) gene overexpression has been reported in the majority of acute myeloid leukemia (AML) patients at diagnosis and has been evaluated as prognostic and minimal residual disease (MRD) marker. PATIENTS AND METHODS: WT1 overexpression was evaluated in 68 adult AML patients at diagnosis and at the end of induction using quantitative real-time polymerase chain reaction (PCR).
RESULTS: No significant associations were encountered between WT1 overexpression at diagnosis and other prognostic factors. Complete remission (CR) was achieved in 74% of the patients with WT1 overexpression compared to 80% of patients with normal levels (P = 0.5). No significant associations were encountered between WT1 overexpression at diagnosis and disease-free survival (DFS) or overall survival (OS) (P = 0.6 and 0.3, respectively). At the end of induction, the median duration of DFS in patients achieving ≥ 2 log reduction was not reached compared to only 5 months (range: 2.1-7.9 months) in those attaining <2 log reduction (P = 0.2). The median duration of OS in patients achieving ≥ 2 log reduction was 13 months (range: 0-33.3 months) compared to 7.5 months (5.4-9.6 months) in those attaining <2 log reduction (P = 0.2). The survival at 1 year in patients achieving ≥ 2 log was double the group with <2 log reduction (67% compared to 33%).
CONCLUSION: Our results, although not reaching the level of significance, probably due to the small sample size, still suggest that the early assessment of WT1 transcript level at the end of induction in patients in CR may have a prognostic significance on clinical outcome and may thus be a useful marker for risk stratification especially in patients lacking disease-specific marker.