[CD7 expression and its prognostic significance in acute myeloid leukemia patients with wild-type or mutant CEBPA]

Objective: To analyze the prognostic value of CD7 expression in newly diagnosed acute myeloid leukemia (AML) patients, and to further explore the correlation between CD7 expression and CEBPA mutation, and to clarify the prognostic value of CD7(+) in AML patients with wild-type (WT) or mutant-type (MT) CEBPA. Methods: The clinical data of 298 newly diagnosed non-M(3) AML patients between January 2010 and December 2016 were analyzed retrospectively. The clinical characteristics and prognosis of CD7(+) and CD7(-) patients were respectively compared in all patients, and in patients with WT and MT CEBPA. The relationship between CD7 expression and CEBPA mutation was determined by chi-square, and the effects of CEBPA mutation on survival and prognosis in CD7(+) group by Kaplan-Meier method. Results: In CD7(+) group, the frequencies of CEBPA mutation were 10.1% (single site) and 33.9% (double site) , significantly higher than those of the CD7(-) group (5.3% and 4.2%) (P=0.000) . Subgroup prognostic analysis showed a lower CR rate (P=0.001) and a higher RR (P=0.023) in CD7(+) group comparing to those of CD7(-) group in AML patients with wild type CEBPA. There were no statistical difference between CD7(+) group and CD7(-) group in overall survival (OS) and disease free survival (P>0.05) , while in the CEBPA mutant group the CD7(+) group has higher OS (P=0.019) and DFS (P=0.010) . Based on the CD7 expression and CEBPA mutation, 298 cases were divided into 3 subgroups, named as CD7(+)-CEBPA MT group, CD7(-) and CD7(+)-CEBPA WT group. The 3-year OS of the 3 groups were 80.2%, 48.0% and 30.6%, respectively (P<0.001) , and the 3-year DFS were 74.1%, 37.4% and 22.2%, respectively (P<0.001) . Conclusion: The CEBPA mutation rate was higher in CD7(+) AML patients then that of CD7(-) patients. CD7 expression has opposite prognostic significance in AML patients carrying the wild-type or mutant-type CEBPA. Based on CD7 expression and CEBPA mutation, a new risk stratification model can be established, which is helpful to guide the clinical individualized treatment for AML patients.