Frequency and prognostic impact of FLT3/ITD mutation in patients with acute myeloid leukaemia.

PURPOSE: This study was designed to evaluate the prevalence and the prognostic significance of fms-like tyrosine kinase-3 internal tandem duplication (FLT3/ITD), in acute myeloid leukaemia (AML).
METHODS: We reviewed 123 newly diagnosed AML patients who have been treated at the Clinic of Hematology, Clinical Center of Nis, Serbia, during a 5-year period. The correlation between presence of the FLT3/ITD mutation and the subtype of disease according to FAB classification, white blood cell count, incidence of early relapse (<12 months) and overall survival was studied.
RESULTS: Among 103 patients for whom molecular analyses had been done, FLT3/ITD mutation was present in 46 (44.7%) cases; the highest frequency was seen in the M0 subtype (63.6%), and the lowest in the M1 subtype (16.7%). There were no statistically significant differences in the FLT3/ITD presence for the 3 groups of patients having different leucocyte counts. The FLT3/ITD mutation was associated with a higher incidence of early relapse compared with no mutation cases (78.7 vs. 21.4%; p < 0.001), and with a shorter survival time (<40 vs. >60 months; p < 0.001).
CONCLUSION: The FLT3/ITD mutation is a poor prognostic factor, which occurs frequently in AML, and is associated with higher incidence of early disease relapse and shorter overall survival.