BCRP mRNA and FLT3-ITD are independent poor risk factors in adult patients with acute myeloid leukemia and intermediate or normal karyotype.

PURPOSE: FMS-like tyrosine kinase 3-internal tandem duplication (FLT3-ITD) is aberration associated with poor prognosis in AML. We have analyzed the expression of MDR-1, MRP-1, and BCRP mRNA in relation to FLT3-ITD in 100 AML adult patients with normal and intermediate karyotype.

METHODS: The RQ-PCR method was performed to assess the expression of MDR-1, MRP-1, and BCRP mRNA, and the results were presented as coefficients calculated using an intermediate method according to Pfaffl's rule.

RESULTS: According to univariate analysis, the following pretreatment variables negatively influenced disease-free survival (DFS): WBC count ≥25×109 /L (P=.037), MRP-1 mRNA ≥1.6818 (P=.028), BCRP mRNA ≥1.1892 (P=.004), FLT3-ITD (P=.005) and overall survival (OS): WBC count ≥25×109 /L (P=.031), MRP-1 mRNA ≥1.6818 (P=.01), BCRP mRNA ≥1.1892 (P=.01), FLT3-ITD (P=.001). When all prognostic variables were pooled into a multivariate model, we found that WBC count ≥25×109 /L (P=.026) and BCRP mRNA ≥1.1892 (P=.011). We observed trend in negative influence of FLT3-ITD on DFS (P=.057). BCRP mRNA ≥1.1892 (P=.035) and FLT3-ITD (P=.006) negatively, independently influenced the OS.

CONCLUSIONS: The high expressions of BCRP mRNA calculated with Pfaffl's rule and FLT3-ITD are independent poor risk factors in adult patients with AML and intermediate or normal karyotype.