PROGNOSTIC IMPACT OF BONE-MARROW KARYOTYPE IN CHILDHOOD ACUTE LYMPHOBLASTIC-LEUKEMIA - SWEDISH EXPERIENCES 1986-91

The prognostic value of cytogenetic classification in acute lymphoblas tic leukaemia (ALL) was evaluated in Swedish children below 16 years o f age (n = 372) diagnosed between 1986 and 1991. A bone marrow karyoty pe was obtained in 281 cases, of which 149 (53%) showed clonal abnorma lities, Event-free survival (p-EFS) was 0.64-0.69 in patients with dip loid and pseudodiploid karyotype. Patients with massive hyperdiploidy (> 50 chromosomes) had the best outcome (p-EFS = 0.76) and those with hypodiploidy (< 46 chromosomes) had the worst (p-EFS = 0.33). White bl ood cell count and age were the strongest predictors of outcome. The k aryotype reached borderline significance. The diagnostic karyotype was also a predictor of outcome after relapse, with hyperdiploid patients doing better than the others. The presence of a structural chromosoma l abnormality did not constitute a negative prognostic factor when int ensive chemotherapy was given.