DNA Content of Tumor Cells. III. Mosaic Composition of Sarcomas and Carcinomas in Man<xref ref-type="fn" rid="fn1">2</xref>

Abstract

Microspectrophotometric measurements were made of the deoxyribonucleic acid (DNA) content of cells from 8 human tumors, which included carcinomas of the intestine, stomach, breast, and bronchi and sarcomas of the colon and bone. The two-wavelength method of Patau was applied. The DNA content of interphase nuclei was compared with the amount of DNA in metaphase plates and early telophase nuclei. A tumor may consist of a relatively homogeneous population of cells with a DNA content deviating from a normal diploid value. Most of the sarcomas and carcinomas exhibited various degrees of mosaic composition, which may be limited to nondividing cells but may be present also in the dividing cell population. In some tumors, only cells with a particular DNA content complete a mitosis, while in other neoplasms, several different cell types are able to divide. Two stemlines, each characterized by a particular aneuploid DNA content, were present in a carcinoma of the breast. A metastasis may consist of cells with an amount of DNA differing from that present in the stemline of the primary tumor. The question is discussed whether all cells present in a tumor can be considered malignant.