Immunocytochemical assay of estrogen receptors in endometrial carcinoma with monoclonal antibodies. Comparison with biochemical assay

Specimens of endometrial adenocarcinoma, surgically obtained from 18 women, were analyzed for distribution of estrogen receptors by an immunocytochemical assay, employing monoclonal anti‐estrophilin antibodies and the peroxidase‐antiperoxidase technique. Results were compared with biochemical receptor analyses, and were in concordance in 83% of them. Marked tumor cell and tissue receptor heterogeneity were apparent with the immunocytochemical method, and a variety of patterns of nuclear staining in positive tissue samples were revealed. These results indicate that the immunohistologic method will provide a number of entirely new variables that may eventually be correlated with both clinical and pathologic features of this malignancy, and may prove to be of value in the prediction of clinical endocrine response.