Application value of quantitative monitoring of RUNX1-RUNX1T1 fusion gene in pediatric acute myeloid leu-kemia / 中华实用儿科临床杂志

ABSTRACT

Objective To explore the prognostic value of quantitative monitoring of RUNX1-RUNX1T1 fusion gene in pediatric t(8;21)/RUNX1-RUNX1T1 positive acute myeloid leukemia(AML).Methods A total of 81 new-ly diagnosed AML children with t(8;21)/RUNX1-RUNX1T1 positive were enrolled in the People′s Hospital,Peking University,between August 2005 and January 2016.RUNX1-RUNX1T1 gene copy number of all the patients was analyzed by real-time quantitative PCR(qPCR)technology at diagnosis and after therapy in all patients.Cumulative incidence of relapse rate(CIR),event-free survival(EFS)rate and overall survival(OS)rate were estimated by Ka-plan-Meier method and prognostic factors were evaluated by COX regression. Results The level of RUNX1-RUNX1T1 gene on diagnosis was used as the baseline to determine whether the level of gene after treatment had a more than 3 logarithmic(3 log)reduction.After 2 courses of induction therapy,the patients with a more than 3 log reduction of RUNX1-RUNX1T1 transcript levels(≥3 log)had better EFS rate(82.4% vs.57.6%,χ2=7.454,P<0.01),and better OS(93.6% vs.59.3%,χ2=9.703,P<0.01),compared to the patients with a less than 3 log reduction(<3 log).Multivariate analysis showed that 3 log reduction in RUNX1-RUNX1T1 transcript levels after 2 courses of in-duction therapy was an independent prognostic factor for EFS rate[hazard ratio(HR)=4.223,95% confidence interval (CI)1.507-11.836,P<0.01]and OS rate(HR=5.002,95%CI1.282-19.516,P<0.05).When periodically monitoring the RUNX1-RUNX1T1 gene,63 out of the 81 children patients were monitored for more than 6 times.The patients who had a more than 3 log reduction of gene before,but then those whose gene transcript level rose more than 1 log level were divided into group A,and the remaining patients were divided group B,and the difference of CIR was statistically significant between group A and group B(46. 7% vs. 4. 7%,P <0. 01). Conclusions RUNX1-RUNX1T1 gene copy number was detected with qPCR method in pediatric t(8;21)/RUNX1-RUNX1T1 positive AML,which can determine the treatment effect,predict the recurrence of patients and assess long-term prognosis.Thus it has great clinical application value.