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Background: Aberrant expression of NK and T cell antigens NKT in AML blasts is ell knon.Hoever,their influence on EFS after standard first line AML induction x0026; OS has not been ell studied.We conducted such an analysis in AML ith normal cytogenetics.We also studied the prognostic significance of NKT expression in FLT3 x0026; NPM1 negative cases. Methods: A retrospective analysis of 266 cases of AML over 10 years as conducted. Flo cytometry done at the time of initial diagnosis as available for 201 of the 266 cases.NKT cell markers such as CD2,CD3,CD5,CD7 x0026; CD56,available in 83 cases,ere analyzed.NKT positivity threshold as set at 20 percent of the gated blast population. EFS and OS ere compared beteen NKT+ and NKT- groups using log-rank testsKaplan-Meier curves.FLT3 and NPM1 proportions in NKT+ and NKT- cases ere compared using Fishers exact test. Results: NKT+ and NKT- frequencies ere 46 percent 3883 and 54 percent 4583 respectively. Amongst NKT+ cases CD56 67 percent as the most commonly expressed marker and x0022;AML ith myelodysplasia related changesx0022; 47 percent as the most common subtype. Amongst AML cases in hich cytogenetic analysis as performed n = 198 , 72 cases had normal cytogenetics AML CyNO .Within this group 41 71.9 percent ere NKT+ and 16 28.1 percent ere NKT-.While trends demonstrated an inferior EFS and OS in NKT+ cases,given our small sample size,statistical significance as not reached. EFS of NKT+ as 0 eeks 95 percent CI:0-20 versus 15.6 eeks 95 percent CI:0-36 in NKT- p = 0.515 .Median EFS for NKT+ and NKT- as 3.6 eeks 95 percent CI:0-24 .OS for NKT+ as 32 eeks 95 percent CI: 12-96 versus 112 eeks 95 percent CI: 28-163.2 in NKT- p = 0.077 .Median OS for NKT+ and NKT- as 47.9 eeks 95 percent CI:28-112 . In FLT3- and NPM- AML CyNO cases both EFS 0 versus 3.6 eeks and OS 24 versus 120 eeks shoed a statitically insignificant trend toard inferior survivals in NKT+ arm.FLT3 or NPM1 distribution as not statistically different beteen NKT+ and NKT- cases in AML CyNO. Conclusions: When knon confounding lohigh risk cytogenetic abnormalities affecting survival in AML ere eliminated, trends suggested orse survivals for AML CyNO NKT+; hoever they failed to reach statistical significance. We are therefore currently analyzing a larger cohort.,J Clin Oncol 34, 2016 suppl; abstr e18502 ,Publication Only Hematologic Malignancies Leukemia, Myelodysplastic Syndromes, and Allotransplant