COMPARATIVE CYTOGENETIC AND DNA FLOW CYTOMETRIC ANALYSIS OF 150 BONE AND SOFT-TISSUE TUMORS

Samples from 48 benign and 102 malignant bone and soft-tissue tumors were analyzed cytogenetically and by DNA flow cytometry. Clonal chromosome abnormalities were found in 82 tumors and normal karyotypes in 68; 61 tumors were DNA-non-diploid and 89 were diploid. The cytogenetically abnormal tumors were used for comparison between the 2 types of investigation; 45 of these tumors were DNA-diploid and 37 were DNA-non-diploid. There was, with few exceptions, good correspondence between the quantitative estimates of genomic changes by the 2 methods, indicating that the cells cytogenetically analyzed from short-term cultures are representative of the in vivo cell populations. Discrepancies were primarily found in cases with indexes above 1.5, in which the DNA index was higher than the chromosome index. The chromosome analysis suggested that skewed stemline (G0/G1) peaks in the diploid region in DNA histograms indicate the presence of cell populations with small net quantitative genomic changes, although not all such populations were detected by DNA flow cytometric analysis. The view that one of the peaks in bimodal stemline DNA histograms with narrow peaks represents a non-diploid cell population was also corroborated. On average, the cell populations giving rise to double stemlines in DNA histograms showed quantitatively larger genomic changes than those that gave rise to broad or skewed diploid G0/G1 peaks. The findings indicate that these histogram profiles are not artifactual but reflect chromosomal changes in the tumor parenchyma.