ESTROGEN AND PROGESTERONE RECEPTORS IN BREAST-CANCER - COMPARISON BETWEEN ENZYME-IMMUNOASSAY AND COMPUTER-ASSISTED IMAGE-ANALYSIS OF IMMUNOCYTOCHEMICAL ASSAY

Evaluation of estrogen (ER) and progesterone (PR) receptor content is now an important procedure in the management of breast cancer patients , Production of monoclonal antibodies to ER and PR has permitted devel opment of an enzyme immunoassay (EIA) and immunocytochemical assay (IC A). This study compared the results of ICA and EIA to evaluate ER and PR in 197 breast cancers using the same monoclonal antibodies. The ICA results were obtained by automated computer-assisted image analysis u sing CAS 200. The cut-off values adopted were 15 fmol/mg protein for E IA and 10% of the positive neoplastic area of the nuclei for ICA. For statistical analysis, Spearman's correlation coefficient and chi(2) we re used, There was good correlation between ICA and EIA for both ER (r = 0.714; P < 0.0001) and PR (r = 0.815; P < 0.0001), Of 197 tumors, 1 36 (69.04%) were ER-ICA(+), and 138 (70.05%) were ER-EIA(+); 111 (56.3 5%) were PR-ICA(+), and 115 (58.38%) were PR-EIA(+). Results were conc ordant, positive or negative with both methods, in 175 cases for ER an d in 173 cases for PR, ER and PR results were only discordant in 22 an d 24 cases, respectively. Concordance of results obtained by the two m ethods was 88.83% (P < 0.0001) for ER and 87.81% (P < 0.0001) for PR, Correlation of results obtained by EIA and ICA to determine ER and PR was good, The data obtained suggest that ICA with automated image anal ysis is an effective means for evaluating ER and PR content in human b reast cancer, especially when, as happens ever more frequently nowaday s, the tumor is too small to perform EIA or when retrospective studies are performed. (C) 1996 Wiley-Liss, Inc.