IMMUNOHISTOCHEMICAL DETECTION OF SEX STEROID-RECEPTORS IN BREAST-CANCER USING ROUTINE PARAFFIN SECTIONS - COMPARISON WITH FROZEN-SECTIONS AND ENZYME-IMMUNOASSAY

Estrogen and progesterone receptors (ER and PR) on 48 surgically remov ed breast cancers were evaluated by three methods: immunoenzymatic (ER /PR-EIA), immunohistochemical in frozen sections (ER/PR-ICA), and immu nohistochemical in paraffin sections (ER/PR-PAR). The monoclonal antib odies H222 and KD68 were used for immunohistochemical detection of ER and PR, respectively. Immunohistochemical stains for pS2, an estrogen- regulated protein, were also done for compatibility with previous ER/P R-PAR studies. We assessed concordance with chi-square and Pearson's c orrelation coefficient. We concluded that ER/PR-PAR is the least sensi tive of the three assays (90.9% ER, 88.5% PR) and, until appropriate t echnical and clinical validation is achieved, should not be used as a first-line assay. Also, because of this lower sensitivity, we recommen d that pS2 evaluation always accompany ER/PR-PAR to facilitate distinc tion between clinical negatives and those due to irretrievably lost im munoreactivity. We also conclude that ER/PR-ICA is a good semiquantita tive method that, in combination with ER/PR-EIA, most accurately asses ses receptor status. (C) 1994 Wiley-Liss, Inc.