Detection of clonal karyotypic abnormalities in most patients with acute nonlymphocytic leukemia examined using short-term culture techniques

Abstract

Cytogenetic studies using short-term culture methods, both with and without methotrexate synchronization, were performed on 53 consecutive patients with acute nonlymphocytic leukemia. Among 50 patients with adequate specimens, 42 (84%) showed a clonal karyotypic abnormality. Numerical changes were observed in 22 cases. Chromosome #8 was most frequently gained (eight cases), whereas chromosome #7 was most frequently lost (five cases). Structural rearrangements were detected in 35 cases. A 5q− was seen in three cases, 6q− in two, 7q− in four, standard or variant t(8;21) in four, 11p− in two, t(11q23;−) in two, t(15;17) in four, inv(16) in two, and inv(20) in two. In five patients small abnormal clones were observed, which represented less than 10% of the total cells analyzed. In five other patients the sole abnormality detected was a tiny structural rearrangement. There was no significant difference in remission rate or in survival among groups of patients without clonal abnormality, with a mixture of normal and abnormal karyotypes or with only abnormal cells. Patients who showed complex karyotypes (four or more chromosomal alterations) had a very poor prognosis. In contrast, patients with t(8;21) tended to have a favorable survival outlook. A normal karyotype was associated with an intermediate prognosis.