COMPARISON OF FLOW AND IMAGE CYTOMETRY FOR DNA CONTENT-ANALYSIS OF FRESH AND FORMALIN-FIXED, PARAFFIN-EMBEDDED TISSUE IN BREAST-CARCINOMA

DNA ploidy and S-phase fraction are considered to be prognostic variab les in breast carcinoma, DNA content of 35 cases of breast carcinoma o f varying histologic types and nuclear grades was analyzed by flaw cyt ometry and image analysis in both fresh and formalin-fixed, paraffin-e mbedded tissue, Fresh cell and deparaffinized nuclear suspensions were used for flow cytometry, Fresh and deparaffinized tumor tissue sample s were used for image analysis, The results of analysis for DNA ploidy , DNA index of DNA aneuploid G(0)/G(1) peaks, and S-phase fraction wer e compared in different tissue preparations for both techniques, The t wo techniques produced comparable DNA ploidy results with both fresh a nd formalin-fixed, paraffin-embedded tissue. Sensitivity for detection of DNA aneuploidy was somewhat greater by image analysis, particularl y in deparaffinized tissue, There was 89% agreement in detection of RN A aneuploidy by flow cytometry in fresh and paraffin-embedded, formali n-fixed tissue; the coefficients of variation of the DNA diploid G(0)/ G(1) peaks were much wider in the latter, In image analysis there was 98% agreement between fresh and fixed specimens, Agreement between the flow cytometry and image analysis in fresh specimens was 91%; in depa raffinized nuclear suspensions it was 94%, There is a high degree of c orrelation between the values of DNA index of DNA aneuploid G(0)/G(1) peaks; the estimates of S-phase fraction are much more variable, Resul ts also show a good correlation of the DNA ploidy with the nuclear gra des, Results reconfirm that preferential loss of specific cell populat ions during processing together with sampling error and/or dilutional effect of normal cells present in cell suspensions should be considere d in interpreting the results of flow cytometry and that sensitivity o f image analysis for detection of near diploid DNA peaks is limited, W e conclude that for detection of DNA aneuploid cell populations, a com bination of both techniques is superior to either of them alone. (C) 1 995 Wiley-Liss, Inc.