Prognostic Significance of FLT3 Internal Tandem Duplication in Egyptian Patients with Acute Myeloid Leukemia with Normal or Favorable Risk Cytogenetics

Internal tandem duplication (ITD) of the FLT3 gene (FLT3/ITD) has been linked to poor outcome in acute myeloid leukemia (AML). However, the prognostic value of FLT3/ITD in various cytogenetic risk groups is still a matter of debate. The aim of this study was to evaluate the prognostic significance of FLT3/ITD in patients with de novo AML and normal or favorable risk cytogenetics (NFC-AML). Blood samples from 39 patients with AML were subjected to PCR of exons 14 and 15 of the FLT3 gene. Patients included 25 with normal cytogenetics, 8 with t(15;17), 4 with t(8;21) and 2 with inv(16). FLT3/1ITD was found in 6/39 (15.4%) patients, 4 of them showed normal cytogenetic, 1 positive for t(15;17) and 1 positive for t(8;21). Patients were M1 3/13, M2 2/12, M3 1/9, M4 0/4 and M5 0/1. The patients were followed up for a mean of 34.5 +/- 2.3 months. The complete remission (CR) rates for the FLT3/ITD+ and FLTITD- groups were 50% vs 63.6%, while the relapse rates were 50% vs 28.6% respectively. Interestingly, disease free survival (DFS) at 3 years was significantly different in studied patients: DFS was 5% in patients with FLT3/ITD+ vs 30% of patients with FLT3/ITD- (P = 0.001). Our data suggest a possible high prognostic value of FLT3/ITD in patients with normal/favorable cytogenetics.