DNA measurement by image analysis of paraffin-embedded breast carcinoma tissue. A comparative investigation

Measurement of cellular DNA content may provide useful prognostic information in several human neoplasms. The DNA content by image analysis of fresh tissue has been compared with flow cytometry with good correlation, but the use of paraffin-embedded tissue for image analysis has not been studied widely. This study reports the DNA content of 54 breast carcinomas and compares the results of image analysis of paraffin-embedded tissue and results of image analysis and flow cytometry of corresponding fresh tumors. Image analysis of paraffin blocks and fresh tumors showed comparable results in 51 tumors (94%), whereas 47 tumors (87%) were similar by all three methods. The DNA indices from image analysis of fresh and paraffin-embedded tumors showed significant correlation by linear regression analysis (r = 0.96; P less than 0.001). Discordances between image analysis of fresh and paraffin-embedded tumors are the result of technical problems, such as staining and tissue preservation. Discordances between image analysis and flow cytometry reflect the advantages and pitfalls of the two techniques. These data suggest that image analysis of paraffin-embedded tissue is a viable technique that will permit the performance of retrospective studies with long-term follow-up data for the evaluation of the prognostic significance of DNA content.