FLT3-ITD Mutations in Egyptian Patients of Acute Myeloid Leukemia: Correlation with Cytogenetic, FAB Subgroups and Prognosis.

Abstract

FLT3-ITD mutations are common in AML subgroups, particularly in Acute Promyelocytic Leukemia (APL). It infers poor prognosis in AML patients; however, its prognostic value in APL is still controversial. We aimed to assess the distribution and prognostic value of FLT3-ITD mutation within AML subgroups, focusing on APL. In NCI, Cairo University, 346 newly diagnosed AML patients were included. Morphological, immunophenotypic and cytogenetic analysis were done at presentation and fixed follow-up points with monitoring in follow up visits of patients. FLT3-ITD mutations were detected using RT-PCR. FLT3-ITD mutations were detected in 18.5% of AML patients with significant higher incidence in M3 patients (35.5%, p = 0.027) in comparison to other types. There was significant negative association between FLT3ITD mutations and CD34 expression (p = 0.026). FLT3 wild patients had a significantly better response on Day 35 than the mutant group (p = 0.046). Overall Survival (OS) of the wild group was significantly better than that of the mutant group (p = 0.003). In APL patients, OS of wild-FLT3 patients was significantly better than of those with mutant FLT3 (p = 0.018). In non-APL patients, favorable cytogenetic changes - t(8;21) and inv(16) - are more common in FLT3 wild group (12.8%) than in FLT3 mutant group (6.3%). In non-APL patients, FLT3-ITD mutation retained its adverse prognostic effect (p = 0.016). CD34 expression affected survival in both FLT3 mutant and wild groups. We conclude that FLT3-ITD mutations infer poor prognostic effects both in AML patients generally and in the APL group specifically. CD34 may have a prognostic impact in FLT3-ITD mutant patients, which is to be further investigated.