Ten-year survival of children with acute lymphoblastic leukemia: a report from the Children's Oncology Group

Area of Science:

• Pediatric Oncology
• Hematology
• Clinical Trials

Background:

• The Children's Cancer Group pioneered risk-based treatment for childhood acute lymphoblastic leukemia (ALL) 30 years ago.
• Long-term survival data are now available for a large cohort of patients treated under these protocols.

Purpose of the Study:

• To evaluate the long-term outcomes (event-free survival and overall survival) of risk-adjusted treatment protocols for childhood acute lymphoblastic leukemia.
• To assess the impact of risk stratification on survival rates in a large pediatric ALL cohort.

Main Methods:

• Analysis of long-term survival data (minimum 10-year follow-up) from 3711 children enrolled in risk-adjusted ALL treatment protocols between 1983 and 1989.
• Comparison of outcomes with predecessor studies to determine the significance of improvements.

Main Results:

• Ten-year event-free survival (EFS) was 62% (SD=1%), and overall survival was 73% (SD=1%), representing significant improvements (P < 0.0001) over previous studies.
• A predicted cure rate of 73% was established, considering that 11% of patients with initial relapses survived without further events.
• Significant improvements in 10-year EFS and survival were observed across intermediate-risk, high-risk, and lymphomatous feature groups (P < 0.0001).

Conclusions:

• Risk-based allocation and specific therapeutic modifications, such as delayed intensification and replacing cranial radiation with intrathecal chemotherapy in lower-risk groups, have substantially improved outcomes for childhood ALL.
• This study represents the largest series of children on concurrent studies with over 10 years of follow-up, confirming the long-term efficacy of these risk-adjusted strategies.