Inter-observer reproducibility of HER2 immunohistochemical assessment and concordance with fluorescent in situhybridization (FISH): pathologist assessment compared to quantitative image analysis

Abstract
In breast cancer patients, HER2 overexpression is routinely assessed by immunohistochemistry (IHC) and equivocal cases are subject to fluorescent in situ hybridization (FISH). Our study compares HER2 scoring by histopathologists with automated quantitation of staining, and determines the concordance of IHC scores with FISH results.