Home > E. Pathology by systems > Genital system > Female genital system > Breast > HercepTest
HercepTest
Monday 2 July 2012
HercepTest™ is a semi-quantitative immunohistochemical assay for determination of HER2 protein (c-erbB-2 oncoprotein) overexpression in breast cancer tissues routinely processed for histological evaluation and formalin-fixed, paraffin-embedded cancer tissue from patients with adenocarcinoma of the stomach, including the gastro-esophageal junction.
HercepTest™ with the indication adenocarcinoma of the stomach, including the gastroesophageal junction, is not available on selected markets.
HercepTest™ specifically demonstrates overexpression of HER2 protein.
Positive or negative results aid in the classification of abnormal cells/tissues and provide a basis for Herceptin™ treatment selection.
Decision regarding Herceptin™ treatment should be made within the context of the patient’s clinical history.
HercepTest™ is indicated as an aid in the assessment of patients for whom Herceptin™ (trastuzumab) treatment is being considered.
The US FDA-approved HercepTest is performed using DAKO A0485 polyclonal antibody kit (DAKO Corp, Carpenteria, CA, USA).
Cases are scored by US Food and Drug Administration (US FDA) guidelines before publication of ASCO/CAP guidelines, with immunohistochemistry of 3+ cases staining >10% of tumor cells.
The new ASCO/CAP guidelines created three categories:
negative for HER2 protein overexpression (scores 0 and 1+),
indeterminate (2+),
positive for HER2 protein overexpression (3+).
Score 0: No staining is observed in invasive tumor cells.
Score 1: Weak, incomplete membrane staining in any proportion of invasive tumor cells, or weak, complete membrane staining in less than 10% of cells.
Score 2: Complete membrane staining that is non-uniform or weak but with obvious circumferential distribution in at least 10% of cells, or intense complete membrane staining in 30% or less of tumor cells.
Score 3: Uniform intense membrane staining of more than 30% of invasive tumor cells.
References
High concordance between HercepTest immunohistochemistry and ERBB2 fluorescence in situ hybridization before and after implementation of American Society of Clinical Oncology/College of American Pathology 2007 guidelines. Vergara-Lluri ME, Moatamed NA, Hong E, Apple SK. Mod Pathol. 2012 Jun 15. PMID: 22699517