Frequency and clinical significance of DNA aneuploidy in acute leukemia

Analyses of the cellular DNA content were carried out in 446 patients with newly diagnosed acute myeloid (AML) and lymphoblastic (ALL) leukemias in order to assess the frequency of DNA aneuploidies and its relation to immunologic and morphologic subtypes as well as its prognostic relevance. Based on high resolution FCM analyses and standardized reference measurements, DNA aneuploidies were identified at a similar frequency in children and adults with AML (38.0% and 40.0%) and ALL (40.0% and 37.4%). In AML aneuploid DNA stemlines were significantly less frequent in FAB-M 1 cases as compared to the other morphologic subtypes (p less than 0.05), whereas the degree of DNA aneuploidy was significantly lower in M 1 and M 2 leukemias as compared to the M 4 and M 5 subgroups (p less than 0.05). In ALL non-T/non-B and C-ALL revealed a higher frequency of DNA aneuploidies than T- and Null-ALL cases (p less than 0.05). No differences in the response to induction therapy were found between patients with and without DNA aneuploidy in children or adults with AML or ALL. In the childhood ALL trial BFM 79/81, however, a significantly higher frequency of long term remissions was observed in children with DNA aneuploidy (0.91 versus 0.66 at five years, p = 0.053). A similar though not significant tendency was also revealed from the AML studies BFM 78 in children and 78/81 in adults. In the subsequent studies these differences could not be confirmed at present, possibly because of the considerably shorter observation time.