Comparative single-cell and flow DNA analysis of bone sarcoma

Five chondrosarcomas and seven osteosarcomas were analyzed by single-cell DNA cytophotometry, in both imprint preparations and tissue sections, and by means of flow DNA cytophotometry. A comparative analysis of the DNA distribution curves of each tumor, as determined by these three methods, showed a good correlation with respect to the modal DNA values. In addition, there was a strong correlation between the proportion of tumor cells with an increased DNA value (hyperploid cells) in imprint preparations and in tissue sections of each tumor as determined by single-cell DNA cytophotometry. Flow cytophotometry appears to be the method of choice for the determination of the aneuploid modal DNA value of a tumor cell population, while single-cell cytophotometry of identified cells seems more appropriate for the determination of the proportion of hyperploid cells in a tumor cell population. In this respect, single-cell and flow DNA cytophotometry may be considered complementary. For the demonstration of the existence of aneuploidy in a tumor cell population, however, the three investigated methods seem to be equivalent. Previous studies using single-cell cytophotometry have shown that DNA determinations in chondrosarcoma as well as in other tumors provide significant prognostic information. For routine clinical work, however, as an adjunct to the conventional histopathologic malignancy grading, single-cell cytophotometry is a rather time consuming procedure, while flow cytophotometry offers a rapid and convenient means of determining the nuclear DNA content. The present study clearly showed that flow DNA cytophotometry may be applied to sarcoma of bone.