PB1727 OUTCOME OF CORE BINDING FACTOR ACUTE MYELOID LEUKEMIA IN ADULT PATIENTS

Abstract

Background:Core binding factor acute myeloid leukemia (CBF AML) encodes two recurrent cytogentic abnormalities, t(8;21) and inv (16) and carries an overall good prognosis, yet some cases relapse. Aims:is to define unfavorable group of CBF AML by analysis of (C‐KIT and FLT3‐ITD) and to correlate with outcome of therapy.Methods:Prospective study started at Jan 2015 till June 2017, and included 70 patients CBF AML diagnosed and managed at medical oncology department of National Cancer Institute (NCI), Cairo University. All patients received standard of care protocol at NCI (“3+7”induction followed by 3‐4 courses of high dose cytarabine consolidation. The study was approved by the Institutional Review Board (IRB), of NCI, Egypt.Results:the median age was 31 years (18‐60, with a male/female ratio of 4/3. 42(60%) patients had t(8;21) and 28 patients had inversion 16(40%). C‐KIT mutations (exon 8 and exon 17) were detected in 10/52 tested patients and FLT3‐ITD was detected in 3/70 patients. While patients with Inv.16 had more lymphadenopathy and splenomegaly, median initial leucocytic count and exclusive gum hyperplasia, HCV‐Ab positivity (8/42) was exclusively present in patients with t(8;21). Clinically, lymphadenopathy, pallor and dyspnea were associated with worse overall survival (OS)(<0.05). BM cellularity at day 28 of induction had a significant impact on survival (P = 0.002). Median OS was 19.5 month while median disease free survival (DFS) was not reached for the whole group. Patients with Inv.16 had non‐significant better DFS than patients with t(8;21)(P = 0.07). Neither C‐ KIT D816 V mutation nor FLT3‐ITD mutation had significant impact on OS or DFS, but when taken together (either C‐KIT or FLT3‐ITD mutant) had negative impact on DFS (P = 0.04).Summary/Conclusion:C‐KIT or FLT3‐ITD mutation had negative effect on DFS but not OS. HCV‐Ab positivity may be associated with t(8;21)AML, while Inv.16 is associated with more extramedullary diseaseimage