Acute leukemia is the most common form of cancer in children, comprising approximately 30 percent of all childhood malignancies . Of the acute leukemias, acute lymphoblastic leukemia (ALL) occurs five times more commonly than acute myeloid leukemia (AML). Survival rates for ALL have improved dramatically since the 1980s, with a current five-year overall survival rates estimated at greater than 85 percent [1-4]. This improvement in survival is due to treatment of a large number of children on sequential standardized research protocols. Approximately 75 to 80 percent of children with newly diagnosed ALL participate in such trials, the goals of which are to improve clinical outcomes while minimizing acute toxicities and late-occurring adverse events.
The outcome of ALL in children is reviewed here. Presentation, classification, risk group stratification, and treatment of childhood ALL are discussed separately. (See "Overview of the presentation and diagnosis of acute lymphoblastic leukemia in children and adolescents" and "Risk group stratification and prognosis for acute lymphoblastic leukemia in children and adolescents" and "Overview of the treatment of acute lymphoblastic leukemia in children and adolescents".)
Event-free survival — Event-free survival (EFS) rates for acute lymphoblastic leukemia (ALL) have steadily improved since the 1980s [5-7]. The overall five-year EFS for childhood ALL currently approaches 80 percent in the developed world, and the 10-year EFS is about 60 percent . The five- and estimated 10-year survival rates for patients diagnosed from 2000 to 2004 were 88 and 84 percent, respectively . The 10-year survival rate for children diagnosed in the 2005 to 2009 period is estimated to be 88 percent.
In contrast, in the developing world, cure rates are less than 35 percent , in part because of abandonment of treatment  and/or lack of dedicated, multidisciplinary pediatric oncology units . When children in the developing world are treated on international protocols, rates of EFS and overall survival at five years are improved (74 and 82 percent, respectively), yet treatment-related mortality remains higher than in the developed world (5 percent death in complete remission) . Treatment-related mortality correlates with differences in available supportive care.
Individual prognosis in the developed world varies according to risk group: