Radioimmunohistochemistry was developed for quantitation of epidermal growth factor receptors (EGFR) and thec-erbB-2 protein and applied in breast tumors. With appropriate preliminary development, the method can be extended to other antigens and tissues. Radioimmunohistochemistry has confirmed that relationships between EGFR andc-erbB-2 expression levels and disease endpoints exist that are not apparent when the receptors are measured with existing semiquantitative methods. The technique was pioneered in 1984 (1 ) for measurements of EGFR in squamous tumors and then modified (2 ) and applied to quantify thec-erbB-2 protein in breast carcinomas (3 ) using the ICR12 rat monoclonal antibody (4 ) (Dr. Chris Dean, Institute of Cancer Research, Sutton, London, U.K.). Although radioimmunohistochemistry is conceptually simple and reveals reliable quantitative data, considerable preliminary work is required for each new antigen and the technique itself is time consuming. For these reasons, careful consideration is necessary prior to being committed to a project based on the method. In this chapter, the application of radioimmunohistochemistry for the measurement ofc-erbB-2 expression in frozen sections is described.
