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

The Children's Cancer Group initiated risk-based allocation for childhood acute lymphoblastic leukemia 3 decades ago. Long-term survival data (minimum follow-up >10 years) is now available. About 3711 eligible children were enrolled in risk-adjusted treatment protocols (1983-1989). Ten-year event-free survival (EFS) and overall survival were 62% (standard deviation [SD] = 1%) and 73% (SD = 1%). These data showed a significant improvement (P < 0.0001) compared with the predecessor studies. Since 11% of patients with initial relapses survived without second events, these data predicted a cure rate of 73%. Ten-year EFS and survival were improved significantly for patients with intermediate risk (P < 0.0001), high risk (P < 0.0001) and lymphomatous features (P < 0.0001). Key components of therapies included delayed intensification and substitution of intrathecal chemotherapy for prophylactic/preventive cranial radiation in low- and intermediate-risk patients. This is the largest series of children on concurrent studies who were observed more than 10 years.