Cytogenetic findings in chronic myeloid leukemia (CML); evaluation of karyotype, blast morphology, and survival in the acute phase

Cytogenetic data on a series of 68 patients with chronic myeloid leukemia (CML) are presented, with emphasis on chromosomal findings in 19 patients who either transformed from a chronic to an acute phase (12 cases) or presented in an acute phase (7 cases). Correlation of chromosome patterns, blast morphology, and survival was attempted, following the aims and recommendations of the First International Workshop in Leukemia (Cytogenet Cell Genet (1977): 19, 321). A Philadelphia (Ph1) chromosome was detected in 61 of 68 patients (90%) and identified by banding in 40 cases; 39 patients had the usual (9;22) translocation and one patient showed an unusual (17;22) Ph1 translocation. Clonal abnormalities in addition to the Ph1 were found in 9% of chronic patients whereas 79% of acute patients showed karyotypic clonal evolution. The three most frequently observed patterns of clonal evolution were trisomy 8, two Ph1 chromosomes and an isochromosome 17 (i(17q)). Two Ph1 chromosomes were observed in both chronic and acute cases, but in this series, trisomy 8 and i(17q) were detected only in acute patients. Detection of clonal evolution is generally indicative of an accelerated phase in the majority of cases and the development of an i(17q) clone is particularly ominous. After transformation, no obvious correlation between the pattern of clonal evolution, blast morphology, or survival was found. © 1980.