TREATMENT OUTCOME OF CHILDREN WITH ACUTE LYMPHOBLASTIC LEUKEMIA ACCORDING TO RISK-GROUP STRATIFICATION: 20-YEAR PERIOD EXPERIENCE IN A SINGLE INSTITUTION

Abstract

Background and Aims: Acute lymphoblastic leukemia (ALL) is the most common malignant disease in children and adolescents. In this study, the treatment outcomes and prognostic factors of ALL patients were investigated during a 20-year period in a single institution.

Methods: This study analyzed patients aged < 19 years old who were diagnosed with ALL at Ajou University Hospital from January 2001 to December 2019. Patients were classified and treated under the low-risk(LR), standard-risk(SR),high-risk(HR), and very HR(VHR)groups.

Results: Among 112 patients, there were 7 patients(6.3%) in LR,37(33.3%) in SR, 52(46.4%) in HR, and 16(14.3%) in VHR groups. Relapse occurred in 22 patients, with 15 occurring during ALL treatment and 7 occurring with in a median 18 months following the end of chemotherapy(range,2–53 months). The 10-year relapse-free survival(RFS) and overall survival(OS) were 76.6±4.5% and 83.3±4.8%, respectively. The RFS and OS according to risk groups were as follows: LR:68.6%±18.6%, 80.0±17.9%; SR:83.5%±6.8%, 100%; HR:76.1%±7.3%, 81.1±5.8%; and VHR:63.0%±13.3%, 63.3±16.6%. On multivariate analysis, white blood cell count > 200,000/mm3 at diagnosis(relative risk: 5.120, 95% confidential interval [CI] 1.454–18.028, P=0.011) and BCR/ABL mutation(relative risk:3.863, 95% CI 10.98–13.591, P=0.035) were associated with a lower RFS. On subgroup analysis, the LR group had a lower OS than the SR group(80.0±17.9% vs 100%, P=0.025).

Conclusions: Our study indicated that patients with hyperleukocytosis at diagnosis and BCR/ABL mutation exhibited a lower RFS. The OS of the LR group was lower than that of the SR group.Therefore, the treatment for these patients should be modified to improve the treatment outcomes.