DNA distributions in human normal, precancerous and cancerous breast tissue. I. Ploidy and cell cycle distribution.

DNA distributions were recorded flow cytometrically in 19 normal, 23 precancerous tissues with epithelial proliferation and cell atypia (P1), 7 carcinomata lobularia in situ and intraductale carcinomas (P2) and in 44 invasive carcinomas of the human breast. The results were compared to histological findings, tumor staging and grading, lymph node involvement and age of the patients. DNA diploidy was found in all normal, 21 P1 tissues, 6 P2 tissues and 12 carcinomas; DNA aneuploidy in 2 P1 tissues, 1 P2 tissue and 32 carcinomas. Lobular carcinomas were preferentially involved in the DNA diploid group, duct carcinomas in the DNA aneuploid group. Cell cycle distribution analysis resulted in significantly higher percentages of cells in S- and G2M phase in DNA aneuploid carcinomas compared to normal and precancerous (P1, P2) tissues. The percentage of cells in G2M phase was significantly higher in DNA aneuploid carcinomas originating from patients younger than 50 years compared to patients older than 50 years. Correlations between the DNA-index, cell cycle distribution, lymph node involvement, tumour staging or histological type were not evident.