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e18521Background: AML is a disease with a high number of various mutations and genomic abnormalities; most of them have a proved prognostic value. We focused on FLT3 gene, which shows a high hetero...

7015 Background: Mutations of the FLT3 gene (in special internal tandem duplication -ITD) are common in normal karyotype AML (NK-AML) and are associated with shorter relapse free and overall survival (OS). The frequency of FLT3 mutations is lower in other cytogenetic subgroups and the impact on outcome is unclear. Methods: The records of patients (pts) with newly diagnosed AML (from 2003 to 2007) were reviewed. Pts were divided among three cytogenetic subgroups: Good-risk (t(8;21), Inv(16)/t(16;16)) Intermediate-Risk (Diploid,-Y) and Poor Risk (-5,-7, 11q abnormalities). FLT3 ITD and tyrosine kinase domain (TKD) mutations were determined on baseline DNA samples by a PCR based method with 1% sensitivity. Since the frequencies of FLT3 mutations were lower in good- and poor-risk subgroups, ITD/TKD mutations were considered together in the analysis, while in the intermediate risk group they were analyzed separately. Survival curves stratified by FLT3 mutation were estimated by Kaplan Meier plots and compared by logrank test. A Cox model was fit for OS, and non-significant variables were eliminated in a step-down fashion with a p- value cut-off of p = .10. Results: A total of 481 pts were included (65 pts=good risk, 272 pts=intermediate risk and 144 pts= poor risk). Prevalence of FLT3 mutations is shown in the Table. No difference was found in median OS between FLT3-mutated and FLT3- wild type pts in the good risk group (not reached (NR) vs NR, P = 0.57) nor in the poor risk group (55 vs 24 weeks, P = 0.44). In intermediate risk, OS was worse in FLT3-ITD positive pts (33 vs 89 weeks, P < 0.0001) but not in FLT3-TKD positive pts (77 vs 70 weeks, P = 0.89). In the Cox model, FLT3 mutations were prognostic for OS only in intermediate risk pts with FLT3-ITD (HR 2.63, P < 0.0001). Conclusions: In our cohort of pts, FLT3 mutations did not have a prognostic impact in AML with good and poor risk karyotype. [Table: see text] No significant financial relationships to disclose.

7024 Background: Mutations of NPM1 gene are present in half of patients (pat) with adult AML and normal karyotype and mutated cases have favorable outcome. NPM1 mutations frequently associate to FL...