Prevalence of FMS-like tyrosine kinase 3/internal tandem duplication (FLT3/ITD+) in de novo acute myeloid leukemia patients categorized according to cytogenetic risk

context and objective: the mechanism involved in leukemogenesis remains unclear and more information about the disruption of the cell proliferation, cell differentiation and apoptosis of neoplastic cells is required. design and setting: cross-sectional prevalence study at the discipline of hematology, hospital s？o paulo, universidade federal de s？o paulo. methods: we investigated fms-like tyrosine kinase 3/internal tandem duplication (flt3/itd+) in 40 adult patients with de novo acute myeloid leukemia (aml), categorized according to cytogenetic results, from september 2001 to may 2005. results: thirteen patients (32.5%) were classified as presenting the favorable karyotype, 11 patients (27.5%) as an intermediate group, 7 patients (17%) as an undefined group and 9 patients (22.5%) as the unfavorable group. flt3/itd+ was found in 10 patients (25%): 3 with flt3/itd+ and favorable karyotype; 4 with flt3/itd+ and intermediate karyotype; 2 with flt3/itd+ and undefined karyotype; and only 1 with flt3/itd+ and unfavorable karyotype. among the patients without flt3/itd+, 10 presented favorable karyotype, 8 intermediate, 4 undefined and 8 unfavorable karyotype. the cytogenetic results showed no correlations between flt3/itd presence and the prognostic groups (p = 0.13). we found that 2 patients were still alive more than 24 months later, flt3/itd+ did not influence the patients' survival rate. conclusion: we found the same frequency of aml with flt3/itd+ in both the favorable and intermediate prognosis groups. only one patient presented aml, flt3/itd+ and unfavorable karyotype (the hypothetical worst clinical situation). therefore, the prognostic advantage of favorable cytogenetics among patients with flt3/itd+ remains to be elucidated, for it to be better understood.