Context
Overexpression of the HER-2 oncogene is likely to be both a prognostic and a predictive factor in patients with breast cancer. There is considerable controversy over the best way to test for tumour HER-2 status. This study analysed HER-2 status in archival breast cancer tissue, by assessing the immunohistochemical (IHC) sensitivity of a series of antibodies. HER-2 status was also determined by fluorescence in situhybridisation (FISH) of amplified genes.