Estrogen receptors in carcinoma of the breast. A comparison of the dextran-coated charcoal, immunofluorescent, and immunoperoxidase technics.

This study compares the estrogen receptor (ER) content of 26 breast neoplasms as determined by dextran-coated charcoal (DCC), fluorescein-labeled estradiol conjugate (FITC) on frozen sections, and immunoperoxidase (IP) on sections of formalin-fixed, paraffin-embedded tissues. Concordance between results of the three technics was found in 16 (62%) cases. DCC and IP agreed in 18 (69%) cases, DCC and FITC agreed in 22 (85%) cases, and IP agreed with FITC in 18 (69%) cases. Most of the concordant cases (15/16) were in patients with ER-positive neoplasms. The relative merits and applications of the three technics are discussed.