Prognostic implication of hyperdiploidy as based on DNA flow cytometric measurement in childhood acute lymphocytic leukemia--a multicenter study.

The pretreatment distribution of DNA content was determined in the leukemic blasts of 114 children with standard risk acute lymphocytic leukemia. The patients were admitted to four different centers for pediatric oncology, participating in a national study ALL-V. In 39 of 107 evaluable patients (36.4%), a single aneuploid leukemic line was detected with a median DNA Index of 1.22 (range 1.10-1.40). These hyperdiploid patients did not differ from those with diploid disease for the presenting features of age, sex, FAB classification, immunophenotype, or white blood cell count. However, patients with hyperdiploid acute lymphocytic leukemia had a significantly longer (p = 0.021) disease-free survival after a median observation period of 52 months. These observations indicate that routinely applied flow cytometry of DNA content can identify a fairly large subgroup of children with standard risk acute lymphocytic leukemia who have a low probability of relapse. It may be considered to exempt these patients from more intensive treatment regimens.