HER2-negative breast cancer: Tumor cells lack overexpression/amplification of the HER2 receptor.
- Implication: Does not respond to HER2-targeted therapies (trastuzumab, pertuzumab, T-DXd, etc.).
- Treatment: Managed mainly with endocrine therapy if ER/PR-positive, or chemotherapy if triple-negative.
- Prognosis: Generally less aggressive than HER2-positive, except for triple-negative subtype, which is more aggressive.
Key for oncology pharmacists: HER2 status is critical for therapy selection — HER2-negative excludes HER2-targeted agents.
Synonyms
HER2-