Outcome heterogeneity in childhood high-hyperdiploid acute lymphoblastic leukemia

High hyperdiploidy (HeH) (51 to 65 chromosomes) is found in one third of children with acute lymphoblastic leukemia and is associated with a good prognosis. Cytogenetic features may further refine this prognosis and identify patients with a poor outcome. We examined the effect of sex, age, individual trisomies, modal number, and structural abnormalities on survival among 700 children with HeH. Univariate analysis showed that age. sex, +4, +10, +18, and a high modal number were associated with survival. Multivariate analysis however, revealed that only age, sex, +4, and +18 were independent indicators. Hazard scores for predicting relapse and mortality were constructed. Three risk groups with 5-year event-free survival (EFS) rates of 86%,75%, and 50% (P < .0001) were identified. The high-risk group comprised boys older than 9 years, boys aged 1 through 9 years without + 18, and girls older than 9 years without +18, while girls aged 1 through 9 years with 18 had the best EFS. In terms of mortality, those younger than age 10 years with both +4 and +18 had an improved survival (96% vs 84% at 5 years, P < .0001). These findings confirm that the outcome of children with HeH is heterogeneous and that specific trisomies can identify patients with the greatest and least risk of treatment failure. (C) 2003 by The American Society of Hematology.