Reproducibility of human epidermal growth factor receptor 2 analysis in primary breast cancer - A national survey performed at pathology departments in Sweden.
Background. HER2 is a treatment predictive factor for the effect of trastuzumab and associated with poor prognosis in breast cancer. The analysis of HER2 must be performed with good quality, with regard to both the immunohistochemical (IHC) and in situ hybridization (ISH) analysis. Material and methods. A tissue microarray (TMA) including 11 breast cancer samples was sent twice (once in 2005 and a