More is better! Update of Dana-Farber Cancer Institute/Children's Hospital childhood acute lymphoblastic leukemia trials.

Between 1973 and 1985, 553 children with childhood acute lymphoblastic leukemia were treated on Dana-Farber Cancer Institute/Children's Hospital, Boston, protocols. The programs featured intensive remission induction therapy, CNS treatment with cranial irradiation and intrathecal drugs, doxorubicin intensification with or without asparaginase, and 2-21/2 years of conventional continuation therapy. There has been progressive improvement in event-free survival for each successive program. Leukemia control concerns pertain to: 1. late relapses (at greater than 5 years) in "standard-risk" patients; 2. an increased incidence of CNS relapses, especially in "standard-risk" patients, as preventative treatment is reduced in intensity; and 3. bone marrow relapses in "high-risk"patients. Comparisons of patients receiving the more intensive arm of each protocol with those receiving the less intensive arm support the hypothesis that more intensive chemotherapy results in improved event-free survival.