Studies of the expression of epidermal growth factor receptor in human renal cell carcinoma: a comparison of immunohistochemical method versus ligand binding assay.

We evaluated the expression of epidermal growth factor receptor (EGFR) in 21 patients with renal cell carcinoma (RCC) by immunohistochemical staining of frozen tumor sections using a monoclonal antibody for EGFR and by a ligand binding method using radiolabeled epidermal growth factor. EGFR was detected in 16 of the 21 cases by ligand binding, while 11 of the 21 cases were detected by immunohistochemical staining. A significant correlation was observed between the two methods in detecting EGFR (p < 0.0001). EGFR was detected by the ligand binding method in all patients who died of RCC. Four cases that were graded as EGFR-negative on immunohistochemistry died of RCC. Observations suggest the ligand binding method was more sensitive than the immunohistochemical method in detecting EGFR and forecasting patient survival.