[Long-Term Outcome of 940 Children with Newly Diagnosed Acute Lymphoblastic Leukemia Treated with CCLG-ALL 2008: A Prospective Single Center Study in China].

OBJECTIVE To study the long-term efficacy of CCLG-ALL2008 protocol used for treatment of childhood acute lymphoblastic leukemia (ALL). METHODS Nine hundred and forty children with newly diagnosed ALL from January 2008 to April 2015 were treated with CCLG-ALL2008 protocol. Overall survival (OS) and event-free survival (EFS) rates were estimated by the Kaplan-Meier method. Cox proportional hazards model was used for analyses of prognostic factors. RESULTS Among the 940 newly diagnosed ALL patients, 570 patients were male, and 370 patients were female, the median age of onset was 5 years old (from 1 to 15 years old). The complete reaction rate (CR) was 96.7%. Survival analysis of 916 ALL patients with CR estimated by follow up [ (median follow up period 64 months (from 3 to 123 months) ] showed that, the expected 10 year OS rate was (78.6±1.5)% and the EFS rate was (66.0±1.8)%. The long-term OS rate of standard risk, intermediate risk and high risk patients was (93.0±1.5)%, (77.6±2.7)%, and (59.3±3.7)%, respectively, and the long-term EFS rate in standard risk, intermediate risk and high risk patients was (84.2±2.2)%. (67.8±2.9)%, and (42.1±3.9)% respectively. 10 year OS rate in B-ALL patients (79.8±1.6)% was significantly higher than that in T-ALL patients (53.5±6.3)% (P＜0.01). Among of all the patients, patients 201 (21.9%) relapsed, the median relapse time was 19 months (from 2 months to 81 months). The 10 year EFS rate was (81.7±3.7）% in the patients with MRD rate ＜0.01% after induction therapy, which was significantly higher than that in the patients with MRD rate＞0.01% (48.4±9.8)%. CONCLUSION The therapeutic efficacy of the CCLG-ALL2008 protocol is closed to the level of supior study group in the world. Risk stratification can improve the outcome for childhood ALL. Immunophenotyping shows the outcome of B-ALL is better than that of T-ALL. MRD negative patients after induction therapy shows better prognosis compared with that of MRD positive patients.