[A prognostic factor in childhood acute lymphoblastic leukemia: implication of cellular DNA contents. Children's Cancer and Leukemia Study Group].

The cellular DNA content of marrow blasts were measured by flow cytometry in 250 children with acute lymphoblastic leukemia (ALL). Abnormal DNA stemlines were detected in 51 cases (26%) of 196 children with untreated ALL and in 10 cases (18.5%) of 54 children with relapsed ALL. In untreated cases, the distribution of cellular DNA content for DNA aneuploidy showed that all except one hypodiploid case, had hyperdiploid DNA contents (DI greater than 1.0). Children with hyperdiploid DNA stemline had significantly better prognosis than did those with diploid DNA stemline (DI = 1.0) in both low-and high risk groups; risk assignment was based on an initial WBC count and age at diagnosis. The relative risk of failure to treatment for the hyperdiploid group was one third that of the diploid group in low-risk ALL and one fifth that of the diploid group in high-risk ALL. In relapsed ALL, there was no significant correlation between the cellular DNA contents and their prognosis after relapse. DNA aneuploidy was detected more frequently in late relapsed cases (40%) than in early relapsed cases (6.2%). These results show that cellular DNA content before treatment is an important prognostic factor in childhood ALL.