Abnormal karyotypic clones in human acute leukemia: Their nature and clinical significance

Abstract

Forty-four per cent of 110 unselected patients presenting with acute myeloid, lymphatic, or stem cell leukemia had a karyotypically abnormal, clonal cell line in the bone marrow, and about 60% of these patients also had apparently normal, diploid cells coexisting with the abnormal cells. The karyotypic changes were diverse and distinctive for each patient, but acute lymphatic leukemia tended to hyperdiploidy. The karyotypic changes showed low involvement of F chromosomes, and some excess involvement of C and G chromosomes. There was little evidence of karyotypic evolution. Where therapy induced full remission, abnormal cell lines tended to be replaced by diploid cells. The incidence of karyotypic abnormality at diagnosis was not related to patient age, sex, or type of leukemia. Significantly, the presence of karyotypic abnormality did not influence the chance of leukemic remission or patient survival, except that male patients with C chromosome deficiency survived on average three times longer than those with additional C chromosomes. This study and a review of five other major studies led to the conclusion that karyotypic abnormalities of acute leukemia have little or no etiological, clinical or hematological significance, and do not influence patient survival. It would appear that cell lines characterized by karyotypic abnormality rarely determine leukemic progression, but develop within limits set by a prescribed and individual cell environment.