OBJECTIVETo explore the incidence, clinical characteristics and prognosis of children and adolescents over 10 years of age with acute lymphoblastic leukemia (ALL).

METHODSFrom May 1, 2005 to April 30, 2009, 67 newly diagnosed ALL children and adolescents over 10 years of age were enrolled in protocol of ALL-2005. All of the clinical characteristics of the patients were analyzed. The statistics was done by SPSS 13.0.

RESULTSThere were 40 males (59.7%) and 27 females (40.3%). The mean age at diagnosis was 12.3 ± 1.7 (10.0 to 17.8) years with median age of 12.2 years. Of 67 patients, 48 were in medium risk group, and 19 in high risk group. During induction therapy, 83.6% and 86.6% patients had good response to prednisone and bone marrow blasts ≤ 5% at day 19, respectively. The overall hematologic response rate in these 67 patients was 88.1% (59) in complete remission (CR) after induction therapy, 15 patients relapsed with mean continuous CR period of (14.9 ± 9.9) months. The five-year event-free survivals (EFS) and overall survivals (OS) were (64.4 ± 6.3)% and (74.1 ± 6.1)%, respectively. According to univariate analysis, elevated serum ferritin, bcr-abl translocation, poor response to prednisone, high bone marrow blasts at day 19 or after induction therapy, and high minimal residual disease (MRD) after induction therapy increased risk for recurrence. Multivariate analysis indicated that high MRD after induction therapy was associated with recurrence (RR = 2.20, 95%CI 1.26 - 3.84, P < 0.01).

CONCLUSIONSurvival has improved for children and adolescents with ALL by ALL-2005 protocol. Analysis of serum ferritin and bcr-abl translocation at diagnosis, early responses to treatment and MRD detection during therapy are powerful prognostic indicators.