ABSTRACT
<p><b>OBJECTIVE</b>To explore clinical significance of monitoring the level of minimal residual disease (MRD) at different time point in the risk stratification and prognosis of Childhood B-lineage Acute Lymphoblastic Leukemia.</p><p><b>METHODS</b>Three hundred and eighty cases of children's B-ALL from Augest 2008 to January 2013 in our hospital were enrolled in this study. MRD levels were detected at day 15, day 33 and week 12 after initial chemotherapy. The event-free survival(EFS) and overall survival (OS) were measured on the basis of MRD levels at different stages of chemotherapy and were compared by Kaplan Meier analyses.</p><p><b>RESULTS</b>The patient's age, initial white blood cell count, chromosome, MLL, BCR/ABL, pretreatment reaction, bone marrow MRD at days 33 were closely related with the 5-year EFS rate. Multiparameter flow cytometry showed the marked MRD and unmarked MRD were not significantly different between their 5-year EFS rate(P>0.05), and the every immune phenotype was also no significantly different between the 5-year EFS rate(P>0.05). The children with MRD≥10at day 15(P<0.01), MRD≥10at day 33 (P<0.01) and MRD≥10on week 12(P<0.01) have a decreased 5-year EFS rate and overall survival, which related with poor prognosis obviously. The 5-year EFS rates at the MRD<10(negative), 10-10, 10-10and ≥10at day 33 were 86.6±2.7%, 77.5±4.9%, 70.1±8.0%, and 44.8±9.9%(P<0.01) with significant difference respectively; the 5-year OS rate was 89.5±2.7%, 80±4.9%, 76.0±7.8%, and 53.2±10.1% with statistically significant difference(P<0. 01).</p><p><b>CONCLUSION</b>The MRD≥10at day 33 is a high risk factor for significant reduction of the 5-year EFS rate and the 5-year OS rate of children with B-ALL. Thus, dynamic monitoring the MRD level can predict relapse of B-ALL after remission.</p>
ABSTRACT
<p><b>OBJECTIVE</b>To explore the clinical features and prognostic factors of pediatric acute lymphoblastic leukemia (ALL) in high-risk (HR) group.</p><p><b>METHODS</b>A total of 421 children with ALL in the Children's Hospital of Soochow University from August 2008 to March 2013 were diagnosed and treated according to the Chinese Children Leukemia Group (CCLG)-2008 Protocol. Among different risk-groups, 148 cases were stratified into the low-risk group and 191 cases were included in the moderate-risk group. Eight-two patients of the high-risk group were analyzed retrospectively for their clinical features, 5-year event-free survival (EFS) rate and overall survival (OS) rate.</p><p><b>RESULTS</b>The median follow-up times of 82 patients were 64 months(3.0-76.3 months), 55 patient achieved complete remission(CR) after 1 cycle of induction chemotherapy(CR rate 67.1%), 25 patients relapsed(30.5%) mainly in very early and early relapse phases, significantly different from the low-risk group (P=0.013), 27 pateitns died(32.9%). The 5-year pEFS and pOS were 57.20% and 58.5%, respectively. Phor BCR/ABLand MRD>10on the 33rd day in the high-risk group were 2 main factors influencing EFS and OS according to single factor analysis. Phor BCR/ABLwas an independent prognostic factor, however, the MRD value on the 33rd day was not statistically significant differente by virtue of COX regression analysis.</p><p><b>CONCLUSION</b>The clinical feature of children with ALL in high risk group display low induction CR rate, high recurrence rate and the lower 5-year pEFS. Phor BCR/ABLis regarded as an independent factor of poor prognosis.</p>