Cobleigh MA, Vogel CL, Tripathy NJ, et al. Proc Annu Meet Am Soc Clin Oncol . Slamon D, Leyland-Jones B, Shak S, et al. Proc Annu Meet Am Soc Clin Oncol . The very sensitive serum-based assays would be the easiest to use to test for this alteration, by measuring the extracellular domain of the receptor that is shed, but these are less useful to follow early disease or minimal disease and as screening tools.
Immunohistochemistry is the most commonly used assay.
Gene-based imaging using FISH is a new technique that appears to be superior to immunohistochemistry. Another drawback is that it will miss the single-copy overexpressers. However, except in central laboratories where there is substantial experience with this, the results have been disastrous. You may see some of the additive effects that we ve seen. In the case of the platinum salts, we ve had patients who had failed and then had complete responses to either cisplatin or carboplatin.