Background
Pathologists look for HER2 immunohistochemical expression in breast carcinoma representing HER2 amplification. The used tests are validated for HER2-high, e.g. score 2+ or 3+. Treatment of HER2-low breast carcinoma is emerging for HER2 expressing tumors with a score of 1+ or 2+ without amplification. In this study, immunohistochemical detection of HER2-low is tested for inter- and intralaboratory reproducibility in The Netherlands. Can the HER2-high test be used to detect eligibility for HER2-low treatment as well?
Authors and institutions
Nils ‘t Hart1, Maran Eenkhoorn1, Henrik Høeg2 and David Dabbs3
- Isala, Zwolle, The Netherlands
- Visiopharm, Hørsholm, Denmark
- University of Pittsburgh Medical Center, United States