Cytogenetic study of chronic myeloid leukemia.

A total of 122 patients with chronic myeloid leukemia (CML) were cytogenetically examined. At the first cytogenetic examination 68 of them were in chronic phase (CP) and 54 in blastic phase (BP) of the disease. The mean age of the whole group was 44.8 +/- 15.2 years. All patients included in this study were Ph-positive. In two of them constitutional chromosomal aberrations were ascertained. In two patients the standard Ph translocation was accompanied within onset of BP by a clone with complex translocation and in three patients Ph chromosome was found in mosaics with normal karyotype. Standard translocation t(9.22) (q34;q11) as the sole chromosomal abnormality was found in 17 (31%) patients in BP and in 47 (69%) of patients in CP. The most frequent additional abnormalities found were +8, i(17q), +Ph and their combination, and other nonrandom chromosomal changes. Clonal evolution was proved in 11 out of 24 serially examined patients during the progression of the disease. The analysis of relationship between prognosis of the disease and the results of cytogenetic examination revealed significant differences, and a more favorable course of the disease was observed for the group of patients in CP and with Ph chromosome as the sole chromosomal aberration.