Immunohistochemical Detection of Hormone Receptors in Breast Carcinomas (ER-ICA, PgR-ICA): Prognostic Usefulness and Comparison with the Biochemical Radioactive-Ligand-Binding Assay (DCC)

In a prospective study conducted since 1983, the hormone-receptor status of primary breast carcinomas was investigated using immunohistochemical (ER-ICA, PgR-ICA) and biochemical (DCC) methods. The degree of immunohistochemical staining was evaluated according to the immunoreactive score (IRS) devised by Remmele and Stegner [Frauenarzt 28, 41-43 (1987)]. The findings obtained using the biochemical radioactive-ligand-binding assay (cutoff level, 20 fmol/mg) and those obtained using qualitative immunohistochemical methods were in agreement in 72.5% (ER-ICA) and 72.2% (PgR-ICA) of cases. For the 789 cases of primary breast carcinoma examined, postoperative data were available for a mean follow…