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

METHODSA total of 86 newly diagnosed ALL children and adolescents over 10 years of age (62 cases of B-ALL and 24 cases of T-ALL) were enrolled. Clinical characteristics, therapeutic effect and prognostic factors were retrospectively analyzed. Event-free survival (EFS) and overall survival (OS) rates were estimated by the Kaplan-Meier method. Prognostic factors were evaluated by COX regression analysis.

RESULTSOf 86 patients, 62 were in medium risk, and 24 in high risk. At diagnosis, 53 patients (62%) had hepatomegaly, 50 patients (58%) had splenomegaly, and 46 patients (54%) had lymphoadenopathy. Twenty-nine patients (34%) showed high leukocyte counts (≥50×10/L) at diagnosis. The karyotype analysis was performed on 78 patients. The percentage of hyperdiploidy was 19% (15 cases), and that of hypodiploidy was 5% (4 cases). Eleven patients (14%) had abnormalities of chromosome structure. Of them, one patient was Philadelphia chromosome-positive, and another patient had the t (1; 19) chromosomal translocation. Three patients (4%) were positive for TEL/AML1, 3 (4%) were positive for E2A/PBX1, 6 were positive for BCR/ABL (7%), and 4 (5%) were positive for SIL/TAL1. During 4 weeks of induction therapy, 85 patients (99%) achieved complete remission (CR). In 86 patients, the 5-year anticipated EFS and OS were (64±6)% and (75±5)% respectively. The 5-year EFS and OS in the medium risk group were significantly higher than those in the high risk group (P<0.05). The 5-year EFS in B-ALL patients was significantly higher than that in T-ALL patients (P<0.05). COX multivariate analysis showed that white blood counts at diagnosis and minimal residual disease (MRD) after induction therapy were independent prognostic factors.

CONCLUSIONSChildren and adolescents with ALL over 10 years of age often have clinical characteristics of unfavorable prognosis. White blood counts at diagnosis and MRD after induction therapy may be important factors for the long-term prognosis.