Flow cytometric detection of multifocal DNA aneuploid cell populations in mastectomy specimens containing a primary breast carcinoma

DNA flow cytometry was used to study the presence of DNA aneuploid cell populations in macroscopically normal glandular tissue in mastectomy specimens from 30 patients with breast cancer. In the 13 patients with a DNA diploid primary tumor, no DNA aneuploidy could be found in any of the 39 distant specimens assessed. However, DNA aneuploid cell populations were demonstrated in four of the 17 (23%) patients with a primary DNA aneuploid carcinoma and in seven out of 54 (13%) distant tissue samples (P = 0.02). In all cases the DNA index of the DNA aneuploid cells found in the distant samples was identical to that of the primary tumor. The replicate aneuploid DNA indices and histologic controls taken in parallel very strongly suggest that these distant DNA aneuploid cell populations are metastases.