Explore The Factors Influencing Long-term Disease-free Survival Of Childhood Acute Lymphoblastic Leukemia

Objective: To analyse the treatment outcome of childhood acute lymphoblastic leukemia (ALL) patients in our hospital, and explore the factors influencing the Disease-free survival (DFS) .Methods: 199 children with newly diagnosised ALL from June 2002 to December 2005 were studied. Biological features, therapy-related factors, treatment outcome were compared among the patients with different compliance . Chi-square analysis or Fisher exact test was used to compare differences in the distribution of presenting biological features. The probability of event-free survival (pEFS) was estimated by Kaplan-Meier analysis and the distributions of pEFS were compared by log-rank test.Results: Totally 199 patients were diagnosed to have ALL, of them 140 failed in complying to therapy, containing the patients who didn't receive therapy and who discontinued therapy. The rate of compliance failure was 70.4%. 114 patients completed induction therapy, complete remission (CR) rate was 92.1%.T-immunnophenotyping, Central nervous system leukemia(CNSL), high bone marrow blast cell counts on 19th day of induction therapy was unfavorable. The Probability of 5 years event-free survival (pEFS) of 59 patients comply to therapy was 62.4±9.2% .Significant difference was found among different risk group. 8 cases (13.6%) in 59 patients relapsed (CNSL 4 cases, BM relapse 4cases), and 7 cases(11.9%) died(4 cases died of infection, 3 cases died of hemorrhage).The infection was associated with intensity of therapy, bone marrow depression. The rate in induction period is highest (67.5%). Acute respiratory distress syndrome occurred in 6 cases (10.2%) of 59 patients, who were in maintaining therapy, and 2 cases died.Conclusions: The most important factor influencing EFS of childhood ALL was whether the patients receive therapy. Therapy rate in our province is low, especially in country. It is indispensable to establish perfect hospitalization insurance system. EFS after therapy was due to clinical risk classification, therapy compliance, therapy-related death and relapse. Risk classification is significant to guide therapy and improve EFS. Further study is necessary to establish exact classification.