Cytogenetic studies in adult acute leukemias.

Thirty-six patients with acute leukemia (31 with AML, 5 with ALL) were classified by FAB criteria, and their bone marrow cells were analyzed cytogenetically with G-banding. Chromosomal abnormalities were found in 16 patients (44%). The most common abnormality was an 8;21 translocation, accounting for 19.4% of all AML patients, that was restricted to patients with M2. In 29 treated AML patients, those with an 8;21 translocation [t(8;21) patients] showed a higher complete remission rate (83%) and a longer median survival (10.7 months) than did other patients with AML; patients with only abnormal metaphases (AA patients) had the lowest complete remission rate (33%) and shortest median survival (2.7 months). There was no difference in the remission rate and survival between patients with only normal metaphases (N patients) and patients with abnormal metaphases (A patients). Three out of five patients with ALL had karyotypic abnormalities; the Philadelphia (Ph1) chromosome was found in one case.