INCIDENCE OF CHROMOSOME-ABNORMALITIES AND CLINICAL-SIGNIFICANCE OF KARYOTYPE IN DENOVO ACUTE MYELOID-LEUKEMIA

Cytogenetic studies with high-resolution banding were performed on spe cimens from 132 consecutive patients with de novo acute myeloid leukem ia (AML). All patients were treated according to therapeutic protocols in the same institution. Clonal abnormalities were detected in 97 of the 124 patients in whom an adequate number of mitoses was obtained (7 8.2%). Neither sex, FAB classification, WBC, or the extent of bone mar row infiltrate affected the rate of chromosomal aberrations, whereas p atients younger than 40 years had a greater proportion of normal karyo types (p = 0.047). Two different chromosomal classifications were eval uated: the presence of normal and abnormal metaphases (NN-AN-AA classi fication), and a classification in cytogenetic categories, the latter being based on the frequency of cytogenetic abnormalities. Both classi fications were found to correlate significantly with the clinical outc ome. They also showed independent prognostic significance when age, se x, and FAB morphology were considered in a multivariate analysis. Two abnormalities were closely associated with specific clinical-pathologi c subsets of AML. All the 15 patients with t(15;17) had acute promyelo cytic leukemia; this translocation was not found in any other subset o f AML. Eight of the nine patients presenting rearrangements at 11q23 b elonged to a FAB subset with monocytic differentiation (M4 and M5). Ou r data suggest that cytogenetic findings should influence the therapeu tic approach to AML. In particular, young patients with karyotypes ass ociated with poor responses may be considered for more eradicating tre atments, including allogenic bone marrow transplantation.