Clinical Features And Prognosis Of Children With Relapse Of Acute Lymphoblastic Leukemia

Objective To explore the clinical features and prognosis in children with relapse of acute lymphoblastic leukemia(ALL).Methods Four hundred and fifty-two cases diagnosed acute lymphoblastic leukemia(ALL) were enrolled in this study from August 2008 to May 2013. Four hundred and forty-nine patients were analyzed by flow cytometry for immunophenotypes, 399 cases with B-lineage, 41 cases with T-lineage. All patients were classified into different risk groups according to the protocol of Chinese Children Leukemia Group(CCLG)-2008-ALL. Ninty-five cases was found relapse of ALL after regular examination of the bone marrow and cerebrospinal fluid, including 85 cases with B-lineage. Three hundred and forty-five cases with continuous complete remission(CR) were regarded as the control group. Clinical features and the 5-year event-free survivial(EFS) rate were compared by Kaplan-Meier curves between the relapse group and the control group.Results The number of isolated relapse of bone marrow(BM)was 84 cases(89%), more than extramedullary relapse. Five patients with central nervous system leukemia, Four patients with testicular leukemia and 2 patients with combined recurrence. Compared the relapse group with the control group, statistic difference was found among age, initial white blood cells count and prednisone’s sensitive pretreatment(P=0.03, P=0.021, P=0.026). Evaluation of minimal residual disease(MRD) at day 33 and in week 12, the values of the MRD≧10-2 at day 33 and MRD≧10-3 in week 12 were more than the control group(P <0.001). The 3-year EFS rate with BM relapse was(34±13.7)%. Difference of EFS was found in patients with BM relapse among three groups, they(namely very early relapse group, early relapse group and late relapse group) were(11.5± 7.8)%、(34.1± 9.8)% and(61.6±6.1)%, respectively P<0.05. Prognosis of the very eraly relapse group was inferior to that of late relapse group(P<0.001). The EFS rate of the standard-risk(SR) group was(50±10.9)%, intermediate-risk group(IR) group was(32.3± 6.4)%, and high-risk(HR) group was(26.3± 3.7)%. There was no significant difference between the different risk groups. The recurrence time for T-ALL and B-ALL were(13.16±2.89) month and(23.19±1.51) month, respectively, and the EFS rate were(11.1±5.4)% and(39.6±4.7)%, respectively. There was significant difference in time of relapse and the EFS rate between two groups(P=0.03).Conclusion 1) The clinical features in relapse group were different to the control groups. They included old age(≧10 years), high WBC counts and non-sensitive prednisone’s pretreatment at dignosis. 2) Compared B-ALL, patients with T-cells’ ALL had high percentage of CNSL and low EFS rate. 3) Dynamic evaluation of MRD values can predict relapse and the prognosis of B-ALL. Values of MRD≧10-2 at day 33 and MRD≧10-3 in week 12 have been regarded as carry a high risk factors of recurrence. 4) Very early relapse, isolated BM relapse, T-lineage and the high value of MRD at day 33 were high-risk factors related to prognosis for children with relapse of ALL.