[Experimental and clinical study on flow cytometric DNA analysis of human breast carcinoma].

Flow cytometric DNA analysis was performed on four human breast carcinoma xenografts serially transplanted into nude mice (MX-1, T-61, R-27 and MCF-7) together with 31 surgical specimens of breast carcinoma. Mechanically dissociated tumor cells were stained with propidium iodide and histograms were obtained by counting at least 2 x 10(4) cells using EPICS-V flow cytometer. Tumor ploidy was expressed as DNA Index using internal standard of chicken red blood cells and the percentage of cells in the S phase of cell cycle was determined by Bagwell's program. All of four xenografts and 23 of 31 clinical specimens showed non-diploid pattern. Statistically significant correlation was observed between %S and tumor doubling time of human tumor xenografts, viewed rapid growing tumor revealed high %S. In clinical cases, statistically significant correlation was present between %S and histological grade and the state of hormone receptors. Histological grade III tumors had a significantly higher %S than that of histological grade I tumors. ER negative tumors showed a significantly higher mean %S than that of ER positive tumors. Similarly, PgR negative tumors possessed a significantly higher mean %S than that of PgR positive tumors. However, no significant correlation was found between ploidy pattern and clinicopathological parameters. It was concluded that flow cytometric %S might be useful to estimate the biological malignancy of human breast carcinomas.