INTRATUMORAL HETEROGENEITY OF DNA-PLOIDY IN BREAST CARCINOMAS - A FLOW CYTOMETRIC ASSESSMENT OF SAMPLING TECHNIQUES

Intratumoral heterogeneity of DNA ploidy has been identified in breast carcinomas; however, optimal sampling methods have not been determine d, In this study of 28 invasive breast carcinomas measuring more than 1.4 cm in greatest dimension, two different techniques for obtaining c ells for flow cytometric DNA ploidy analysis were compared, Two solid pieces of tissue were taken from opposite halves of the tumor, A third sample was obtained by scraping multiple cut surfaces of the tumor, H eterogeneity of DNA ploidy was detected in 43% of cases. Most cases de monstrating heterogeneity contained multiple aneuploid populations, Ho wever, in five cases classification of the tumors as either DNA euploi d or DNA aneuploid differed among samples, A total of 39 non-diploid p opulations were detected in 23 of the cases, Thirty-three (85%) were d etected by scraping and 35 (90%) were detected in either one or both t issue pieces, Intratumoral DNA heterogeneity emphasizes the need for a dequate sampling, The scraping technique was as effective in identifyi ng aneuploid cell populations as the combined results of the two piece s of tissue and better than sampling a single piece of tissue, Scrapin g also offers the advantage of tissue conservation which may be critic al when various analytic studies are performed. (C) 1995 Wiley-Liss, I nc.