Immunohistochemical determination of estrogen and progesterone receptor status in breast cancer

Immunohistochemical staining of fresh frozen tissue to identify estrogen and progesterone receptors was tested as a means to supplant the dextran-coated charcoal assay in a small community hospital. Forty-three tumors were compared, yielding an overall concordance of 88% between immunohistochemical staining and the dextran-coated charcoal assay for determination of combined estrogen/progesterone receptor status. In addition, there was greater than 70% concordance for semiquantitative grades. Staining also revealed many other advantages, such as a 65% reduction in costs. For these reasons, the authors have abandoned the dextran-coated charcoal assay in favor of staining for estrogen/progesterone receptor status.