Clinical analysis of pediatric acute myeloid leukemia with EVI1 gene positive

Abstract

Objective To analyze the clinical features and prognosis of pediatric acute myeloid leukemia(AML) with EVI1 gene positive. Methods The nested RT-PCR was performed to detect the EVI1 expression in pe-diatric AML patients from Jan. 2009 to Dec. 2011. The patients with EVI1 were investigated on clinical features, curative effects and prognosis. The differences between EVI1(+) and EVI1(-) patients were also analyzed. Results The frequency of EVI1 (+) expression was 15.65%(13/83 cases)in pediatric AML, with the highest incidence in high-risk patients. EVI1(+) was obviously associated with some unfavorable molecular genetic changes such as complex karyotype, MLL rearrangement, and monosomy 7. There were significant differences for EVI1(+) group and EVI1(-) group in the complete remission rate (45.5% vs 79.3%, χ2=5.497, P<0.05) and complete remission(CR) rate after the first chemotherapy (18.2% vs 63.8%, χ2=7.828, P<0.01). Although significant difference in death rate was not observed, EVI1(+) group had significantly higher early-death rate (45.5% vs 8.6%, P<0.01). The EVI1(+) group also had lower 4 years event-free survival (EFS) [(21.2±13.8)% vs (50.2±9.1)%, χ2=4.493, P<0.05] and lower 4 years overall survival(OS) [(32.4±7.1)% vs (60.3±10.9)%, χ2=4.602, P<0.05] compared with EVI1(-) group. But binary Logistic analysis did not identify EVI1(+) as an independent unfavorable prognostic factor. Conclusions The pediatric AML with positive EVI1 expression had lower CR rate, higher early death rate and lo-wer EFS. Positive EVI1 expression is related with an adverse outcome, but is not an independent poor prognostic factor. Key words: Acute myeloid leukemia; EVI1 gene; Prognosis; Child