Clinical features and implications of childhood acute lymphoblastic leukemia with E2A/PBX1 fusion gene

Abstract

Objective To explore the clinical features and prognosis in childhood acute lymphoblastic leukemia(ALL) with E2A/PBX1 fusion gene. Methods From Jan.2007 to Dec.2011, E2A/PBX1 fusion gene from bone marrow sample in 450 newly diagnosed childhood patients with ALL was evaluated by nested reverse transiption-polymerase chain reaction (RT-PCR). Cases with B-lineage ALL accounted for 4.76% (20/420 cases). The patients with E2A/PBX1 gene were classified to the intermediate-risk group, and 85 cases with negative E2A/PBX1 gene were regarded as control group at the same time.Clinical characteristics, 5-year event-free survivial (EFS) rate and overall survi-vial(OS) rate were compared between 2 groups. Results Statistic differences were not found in age, gender, initial white blood cell count, hemoglobin level between 2 groups(all P>0.05). Level of minimal residual disease(MRD)was lower in E2A/PBX1 fusion gene group than that in control group at day 33 of induction chemotherapy(χ2=15.78, P=0.001). The 5-year EFS rates were (84.4±15.6)% and (73.5±15.6)%, respectively in 2 groups.The OS rates were (86.0±17.6)% and (81.8±17.6)%, respectively.The relapse rates were 10.5% and 12.9% and the median times of relapse were(8.9±5.3)months and(26.2±8.0)months, respectively.There was no significant differences in EFS rates, OS rates, relapse rates and median times of relapse between 2 groups(all P>0.05). Conclusions There was no significant differences between the E2A/PBX1 gene group and control group.E2A/PBX1 fusion gene plays an intermediate-risk role in pediatric B-ALL. Key words: Acute lymphoblastic leukemia; Child; E2A/PBX1 fusion gene; Clinical characteristics; Prognosis