Quantitative measurement of HER2 expression in breast cancers: comparison with “real world” routine HER2 testing in a multi-center Collaborative Biomarker Study and correlation with overall survival

In this study, we compared quantitative HER2 expression by the HERmark® Breast Cancer Assay (HERmark) with routine HER2 testing by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), and correlated HER2 results with overall survival (OS) of breast cancer patients in a multi-center Collaborative Biomarker Study (CBS). Methods: 232 formalin-fixed, paraffin-embedded breast cancer tissues and local laboratory HER2 testing results were provided by 11 CBS sites. HERmark assay and central laboratory HER2 IHC re-testing were retrospectively performed in a blinded fashion. HER2 results by all testing methods were obtained in 192 cases. Results: HERmark yielded a continuum of total HER2 expression (H2T) ranging from 0.3 to 403 RF/mm2 (~3 logs). The distribution of H2T levels correlated significantly (p 
Source: Breast Cancer Research - Category: Cancer & Oncology Authors: Source Type: research