Résumé
Objective To explore the prognostic significance of bone marrow examination at different time points by using different methods during induction therapy.Methods From Feb.2004 to Jan.2013,268 newly diagnosed (B acute lymphoblastic leukemia,B-ALL) pediatric patients in Peking University People's Hospital,were enrolled for the study.In this study,the overall survival (OS) ratio and event-free survival(EFS) ratio of patients with different bone marrow morphology on day 8 and day 15 were analyzed.Based on different cut off value of minimal residual disease (MRD) on day 15 and end-of-induction,the OS ratio and EFS ratio of the higher patients and the lower patients were compared.Results Patients with M1,M2 or M3 marrows on day 8 had no significant difference in OS ratio (P =0.372) or EFS ratio (P =0.393).When it came to day 15,patients with M1,M2 or M3 marrows had no significant difference in OS ratio (P =0.050) or EFS ratio (P =0.324).Patients with MRD ＞ 10.00％ on day 15 had lower OS ratio than those with MRD ≤ 10.00％,and it had significant difference(P =0.022).But there was no significant difference in EFS ratio (P =0.191).As for MRD on the end-of-induction,when using the MRD level of 0.0l ％,0.10％,1.00％ as cut-off values,the lower group of end-of-induction MRD was significantly associated with a higher probability of OS ratio and it had significant differences(P =0.018,0.006,0.002),and it showed the same results at EFS ratio (P =0.002,0.000,0.000).Conclusions The bone marrow morphology on day 8 and day 15 during induction therapy had no prognostic significance.The MRD of day 15 had prognostic significance when using 10.00％ as the cut off value.The critical value of MRD on the end-of-induction MRD should be 0.01％ for the prognosis.