Flow-cytometric demonstration of tumour-cell subpopulations with different DNA content in human colo-rectal carcinoma

Abstract Six consecutively operated colo-rectal carcinomas were subjected to detailed flow-cytometric analysis by taking 6–10 fine-needle aspiration samples from different locations in each tumour. Single-nuclei suspensions were prepared by a detergent technique, and the DNA stained with ethidium bromide. In all 6 carcinomas, tumour cells with “near-normoploid” DNA content were found. In addition, a predominant hyperploid cell population was found in 5 of the tumours, often mixed with the normoploid cells. Thus, colo-rectal carcinomas may be composed of more than one tumour-cell stem line. As these subpopulations probably have a different chromosome content, they may behave differently in several important ways, e.g., in malignant potential. The heterogeneous composition of the tumours may also complicate the interpretation of cell-kinetic and other biological measurements.