Management of children with acute lymphoblastic leukemia by the Dana-Farber Cancer Institute protocols. An update of the Ontario experience.

The primary purpose of this study was to determine the therapeutic efficacy of a protocol of treatment for acute lymphoblastic leukemia (ALL) in children. A prospective approach was adopted with an inception cohort of patients. Outcome measures were assessed on December 31, 1990. The study was conducted at two tertiary care centres (pediatric oncology programs) in Ontario, Canada. All children with ALL were eligible for study and consecutive recruitment took place between May 1984 and July 1987. They were classified at diagnosis into one of three categories for risk of relapse according to standardized criteria. Thirty-nine children were designated as having standard risk (SR), 31 as having high risk (HR), and 12 as having very high risk (VHR) disease. All patients are included in the analysis. Treatment was administered according to risk category-specific chemotherapy protocols, the details of which have been published. A distinguishing feature of these strategies is the intensive use of intramuscular L-asparaginase. Patients remained on these regimens for 2 years or until relapse or toxic death (events) ensued. Total and event-free survival data were determined by life-table analysis (Kaplan-Meier plots). With a minimum interval from diagnosis of 186 weeks and a median interval exceeding 5 years, the cumulative proportion of the entire cohort (C) surviving is 85% [95% confidence interval (CI), 77-93%]. For the respective risk groups, the corresponding proportions are SR 94% (95% CI, 87-100%), HR 74% (95% CI, 59-89%), and VHR 81% (95% CI, 59-100%).(ABSTRACT TRUNCATED AT 250 WORDS)