Prevalence and Clinical Significance of FLT3 Mutation Status in Acute Myeloid Leukemia Patients: A Multicenter Study.

ABSTRACT

BACKGROUND AND AIMS: FLT3-ITD mutations in acute myeloid leukemia (AML) are associated with a poor prognosis. In Latin America, little epidemiological data exist about these mutations and their influence on clinical evolution and prognosis. Standardization and well-established clinical correlation make FLT3 mutational analysis by molecular methods an invaluable tool to decide among treatment options and to determine AML prognosis. METHODS: We assessed the prevalence of FLT3-ITD mutations in 138 patients with AML at four hematology referral centers from Mexico and Colombia. Molecular methods based on polymerase chain reaction (PCR) were employed for determining FLT3-ITD status. RESULTS: Mutations were present in 28 patients indicating a prevalence of 20.28%. Median age was 47 years (5-96). The FLT3 mutation positive group was older, had higher WBC and hemoglobin values and lower platelet counts but without statistical significance. A not previously described mutation in the FLT3 gene was found in one patient involving a nucleotide exchange of timine for cytosine at the 66608 position. A high mortality was found in the FLT3-mutated group, 67.8 vs. 42.72% in the non-mutated group and median survival was 4.9 months vs. 20.4 months, p = 0.009. A mutated FLT3 did not confer poor prognosis to those with M3 AML. The mutated FLT3 population had poor overall survival (OS) despite hematoprogenitor stem cell transplantation (HSCT). CONCLUSION: Prevalence of FLT3-ITD mutation in AML was present in a proportion comparable to other populations and, when present, was associated with a very poor prognosis.