OBJECTIVETo explore the clinical features and survival of patients with CD56 expression in de- novo acute myeloid leukemia（AML）with t（8;21). .

METHODSClinical data of 82 de novo AML with t（8;21）who were newly diagnosed from Jan 2008 to Apr 2014 were analyzed retrospectively, 50 expressed CD56 and 32 not. Clinical characteristics and prognoses were compared between patients expressing and nonexpressing CD56.

RESULTSThere were no statistically significant differences in terms of age, gender, white blood cell count（WBC）, percentage of bone marrow blasts, extramedullary infiltration rate, the early mortality or the presence of additional cytogenetic abnormalities between CD56 + and CD56- groups（P＞0.05). The expressions of lymphatic antigens CD19 between CD56 + and CD56- groups showed significant difference （30.0% vs 53.1% , P=0.036). The complete remission and 3-year overall survival（OS）showed no significant differences between CD56+ and CD56-groups, while 3- year disease- free survival（DFS）showed significant differences（25.8% vs 46.9%, P=0.014). Multivariable analysis for DFS identified CD56 positivity as an independent predictor. DFS of who received allogeneic hematopoietic stem cell transplantation（HSCT）was better than those treated with intermediate- dose cytarabine/high dose cytarabine（IDAC）as postremission therapy.

CONCLUSIONThe expression of CD56 in de-novo AML with t（8;21) appeared to be associated with poorer prognosis.