Chromosomes and causation of human cancer and leukemia. XXIX. Further studies on karyotypic progression in CML.

Fifty-seven Ph1-positive cases of chronic myelocytic leukemia (CML) were analyzed with chromosomal banding techniques and their karyotypic progression followed. These cases included 1 without evidence of a Ph1-translocation and 1 new patient with a complex Ph1-translocation involving chromosomes No. 9, No. 17 and No. 22. Of the 57 patients, 28 had the Ph1 as the only karyotypic anomaly, whereas the remaining 29 cases developed and/or were associated with chromosomal changes usually of a hyperdiploid nature, particularly in the blastic phase, in addition to the Ph1. Even though the additional karyotypic changes frequently included chromosomes No. 8, No. 17, No. 19 and No. 21, a large number of others was also involved, although less often. The series included 3 cases with different types of translocations unrelated to the Ph1. The cytogenetic observations have been correlated with some of the clinical parameters. The survival of the patients was evaluated in relation to the karyotypic findings, indicating that the chromosomal changes may not play as important a role in the prognostic and progressive aspects of Ph1-positive CML as that of other as yet undetermined factors.