Context: Conflicting reports of epidermal growth factor receptor (EGFR) expression in breast cancer and inconstant relationships with established prognostic indicators and outcomes suggest difficulties with EGFR measurement.
Objective: To compare EGFR measurement in a panel of cell lines and in breast carcinomas by radioimmunohistochemistry (R-IHC), conventional immunohistochemistry (IHC), and a ligand binding (LB) assay.
Design: Eight EGFR-expressing cell lines and 50 primary breast carcinoma specimens were analyzed for EGFR by IHC, R-IHC, and LB assays.