Clinical implications of cytogenetic variants in chronic myelocytic leukemia (CML).

By JACQUELINE WHANG-PENG, GEORGE P. CANELLOS, PAUL P. CARBONE AND J. H. Tjio T HE Ph’ CHROMOSOME, with the exception of a few cases of acute leukemia,’5 occurs only in patients with chronic myelocytic leukemia and is still the only consistent chromosome abnormality found in neoplastic diseases.4’9 In about 85 per cent of patients with CML, the Ph1 chromosome is found in most if not all marrow cells. The chromosome does not disappear from the marrow during treatment. There have been reports of development of abnormal cell lines in the acute stage.10’4 In the present paper, cytogenetic studies have been performed on the bone marrow cells from 179 chronic myelocytic leukemia ( CML) patients over the past 7 years at the time of admission to the Clinical Center of the National Institutes of Health. In these 179 patients 88.2 per cent were Ph’ positive and 11.8 per cent were found not to have the Ph’ chromosome. Subclassification of these patients was undertaken on the basis of additional cytogenetic abnormalities; survival was compared in the various groups.