Long-term Results of the Risk-stratified Treatment of Childhood Acute Lymphoblastic Leukemia in China

Long-term follow-up data for childhood acute lymphoblastic leukemia (ALL) are scarce in China because of lacking population-based and hospitalized registry system. This retrospective study, conducted at Shanghai's Children's Medical Center in China (SCMC), aimed to investigate the long-term results of childhood ALL and to identify prognostic factors. The Pediatric Oncology Network Database, designed by St. Jude Children's Research Hospital, USA, were used to collect data for the enrolled patients starting in 2005. From 2005 to 2014, 1085 evaluable patients with ALL aged 1 to 18 years old were enrolled and treated using SCMC-ALL-2005 risk-stratified protocol. Complete remission was achieved in 95.6% of patients. At 5 and 10 years, the event-free survival rate was 68.3 ± 1.4% and 64.6 ± 1.6%, and the overall survival rate was 80.0 ± 1.2% and 76.3 ± 1.6%, respectively. The 5-year event-free survival rates were 81.8 ± 2.0%, 67.0 ± 1.9%, and 14.3 ± 4.0% for patients in low-risk, intermediate-risk, and high-risk groups, respectively. The cumulative risk of relapse was 24.5% at 10 years. Induction failure conferred worse prognosis. Patients younger than 1 year of age at diagnosis, intermediate-risk/high-risk group, male gender, and positive minimal residual disease (MRD) results at day 55, both in the univariate and multivariate analysis, were associated with significantly worse prognosis (P < .05). Patients with positive MRD at both day 35 and day 55 were related to a significantly poor outcome (P < .0001), but not for patients with negitive MRD at day 35. The overall outcomes for ALL patients treated with protocol SCMC-ALL-2005 in SCMC are lower than in developed countries. Factors including age, gender, risk group and MRD results at day 55 were associated with treatment outcomes in childhood ALL.