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 variables in breast carcinoma, DNA content of 35 cases of breast carcinoma of varying histologic types and nuclear grades was analyzed by flaw cytometry and image analysis in both fresh and formalin-fixed, paraffin-embedded tissue, Fresh cell and deparaffinized nuclear suspensions were used for flow cytometry, Fresh and deparaffinized tumor tissue samples 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 were compared in different tissue preparations for both techniques, The two techniques produced comparable DNA ploidy results with both fresh and formalin-fixed, paraffin-embedded tissue. Sensitivity for detection of DNA aneuploidy was somewhat greater by image analysis, particularly in deparaffinized tissue, There was 89% agreement in detection of RNA aneuploidy by flow cytometry in fresh and paraffin-embedded, formalin-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 deparaffinized nuclear suspensions it was 94%, There is a high degree of correlation between the values of DNA index of DNA aneuploid G(0)/G(1) peaks; the estimates of S-phase fraction are much more variable, Results also show a good correlation of the DNA ploidy with the nuclear grades, Results reconfirm that preferential loss of specific cell populations during processing together with sampling error and/or dilutional effect of normal cells present in cell suspensions should be considered in interpreting the results of flow cytometry and that sensitivity of image analysis for detection of near diploid DNA peaks is limited, We conclude that for detection of DNA aneuploid cell populations, a combination of both techniques is superior to either of them alone. (C) 1995 Wiley-Liss, Inc.