Risk Factors Study Of Extramedullary Relapse For Pediatric Acute Lymphoblast Leukemia

Object: Higher extramedullary relapse rate is one of the distinguish features of acute lymphoblast leukemia(ALL),which may cause treatment failure.The main aim of this study is to retrospectively study risk factors correlated to extramedullary relapse.Findings of risk factor may guide our protocol modification in future to avoid relapse and to improve the survival.Methods: Patients who were diagnosed as ALL and treated in Shanghai Children's Medical Center between 2005 and 2014 were studied in this project.The relevant features collected include: 1)general information: age,gender,relapse sites and relapse time;2)biological characteristics: WBC at diagnosis,immunophenotypes and genotypes;3)treatment: the method and dosage of L-asp administration;4)allergy to L-asp.All data were analyzed with SPSS software by using the general statistical methods.The P value less than 0.05 was set to be the criterion for estimating differences.Results: The peak diagnosed age ranges from 2 to 5 years old.The total survival rate of protocol 2009 is higher than that of protocol 2005.For central nerve system relapse(CNSL),LDH above 2000IU/L,being allergic to L-asp and expression of fusion gene E2A-PBX1 were the risk factors with P value less than 0.05.For testicular relapse(TL),allergy to L-asp and shorten L-asp course of treatment were found to be the significant risk factors.Traumatic lumbar puncture and the immunophenotype of the disease was not found to be correlated to either CNSL or TL.Conclusion: ALL Children with higher LDH at diagnosis,being allergic to L-asp,shorten L-asp course of treatment and expression E2A-PBX1 have more possibilities to experience extramedullary relapse.To those patients,special consideration should be made to avoid the adverse events.