Comparison between flow cytometry and single cell cytophotometry for DNA content analysis of the uterine cervix

The DNA content of tumor cells in imprints and biopsies from 33 patients with invasive squamous cell carcinoma and 5 patients with adenocarcinoma of the uterine cervix were analyzed by flow cytometric and single cell cytophotometric methods. A correlation of r = 0.83 was found between the modal DNA values obtained by the two methods. Both methods discriminated between diploid and aneuploid tumors and gave comparable but not identical results. Single cell cytophotometric measurements were in this study more reliable than flow cytometric measurements in diploid tumors. Multiple stemlines, small aneuploid peaks and the so called S-phase rate could only be determined by the flow cytometric technique. Flow cytometry seems to be the method of choice in determination of the DNA content in cervical carcinoma cells and cytophotometric single cell measurements are of complementary value.