Haematologica (May 2010)
Long FLT3 internal tandem duplications and reduced PML-RARα expression at diagnosis characterize a high-risk subgroup of acute promyelocytic leukemia patients
Abstract
Background Internal tandem duplications of the FLT3 gene (FLT3-ITDs) are frequent in patients with acute promyelocytic leukemia (APL), however its clinical impact remains controversial.Design and Methods We analyzed the prognostic significance of FLT3-ITD mutant level and size, as well as FLT3-D835 point mutations, PML-RARα expression and other predictive factors in 129 APL patients at diagnosis enrolled on the Spanish LPA96 (n=43) or LPA99 (n=86) PETHEMA trials.Results FLT3-ITDs and D835 mutations were detected in 21% and 9% of patients, respectively. Patients with increased ITD mutant/wild-type ratio or longer ITD size displayed shorter 5-year relapse-free survival (RFS) (P=0.048 and P