Automated Immunohistochemical Assay for Estrogen Receptor Status in Breast Cancer Using Monoclonal Antibody CC4-5 on the Ventana ES

Guy E. Nichols, Henry F. Frierson, James C. Boyd, Marie H. Hanigan
1996 American Journal of Clinical Pathology  
Determination of breast cancer estrogen receptor (ER) status as a predictor of tumor response to adjuvant endocrine therapy remains a mainstay of breast cancer management. Recent second generation anti-ER antibodies and new epitope retrieval methods have produced paraffinbased immunohistochemical results that correlate closely with the dextran-coated charcoal (DCC) assay and appear to represent a superior method of ER assay. The authors determined the ER status of 103 invasive breast cancers by
more » ... paraffin-based, automated immunohistochemistry on the Ventana ES using a new monoclonal antibody, CC4-5, and compared the results to those of parallel DCC biochemical analysis and manual immunohistochemical analysis using anti-ER monoclonal antibody ERIDS. The specificity of the CC4-5 antibody for ER protein was confirmed by Western blot analysis. Sixty of 103 cases were positive for ER by CC4-S automated immunohistochemistry. With a ligand binding assay threshold value of 20 fmol/mg protein, there were 50 positive cases by biochemical assay. The biochemical results corresponded to an 88% rate of agreement with automated CC4-5 staining. Analysis of discordant cases revealed that the majority of CC4-5 immunopositive only cases (8 of 11) were strongly positive, stroma rich tumors, suggesting that corresponding biochemical measurements were diluted by non representative stromal tissue. There was only one immunonegative, bio- From the
doi:10.1093/ajcp/106.3.332 pmid:8816590 fatcat:gulmpoubh5ga5hnxwiccbvonca