Repurposing HER2 IHC: Pan-HER2 and Low-HER2.
Expanded HER2 testing guidance for new antibody-drug conjugates directly impacts pathology practice and patient access to emerging therapies.
This paper addresses the evolving HER2 testing landscape driven by ADC therapies (trastuzumab deruxtecan) that are active in HER2-low tumors, requiring laboratories to adopt extended IHC scoring. The shift has immediate and direct implications for pathology workflow and patient eligibility determination across multiple cancer types.
What the study was
- Study design
- Review / methods commentary
- Population
- HER2-tested cancer patients (breast, gastric, other)
- Category
- Diagnostics
- Maturity
- Potentially Practice-Changing
- Journal
- Applied Immunohistochemistry & Molecular Morphology
Why it surfaced
HER2-low testing is an immediate, lab-actionable paradigm shift with broad multi-cancer relevance and direct drug eligibility implications; scored HIGH based on near-term implementability and population impact. Evidence maturity = Potentially Practice-Changing given regulatory context.
A plain-language summary of published research — not medical advice. Talk to a clinician about your own care.