HER2
Other names: ERBB2, HER2 overexpression, HER2 amplification, HER2-low
HER2 status is assessed on tissue testing; the result affects treatment categories in stomach cancer and some lung cancers.
Not a diagnosis and not final medical advice. Must be reviewed by a doctor.
Plain explanation
HER2 is a protein on the surface of cells that can promote growth. The number of protein or gene copies is measured from tumor samples.
Clinical meaning
In gastric cancer, HER2 status is often assessed by immunohistochemistry and confirmed by other methods when the results are ambiguous. In lung cancer, HER2 mutations are discussed differently from HER2 amplification.
Testing methods
- Immunohistochemistry (IHC)
A test that uses antibodies to mark specific proteins in tumour tissue.
- FISH (fluorescence in situ hybridisation)
A test that detects changes in the number or arrangement of genetic material in tumour cells.
- Next-generation sequencing (NGS)
A test that reads many genes from one tumour sample to find actionable changes.
- Tumour tissue biopsy
Collection of tumour tissue to confirm the diagnosis and provide material for further testing.
A negative result does not always mean the marker is absent
Test sensitivity differs by sample type and method. Results need to be read together with the pathology report and clinical condition.
What needs verification
- Immunohistochemistry score (e.g. 0, 1+, 2+, 3+) and confirmatory results if available.
- Whether the assessment was performed on primary or metastatic samples.
- Difference between HER2 amplification and mutation in laboratory reports.
- Drug availability and financing terms.
Related drugs
- Trastuzumab
Anti-HER2 monoclonal antibody
- Trastuzumab deruxtecan
Anti-HER2 antibody-drug conjugate
- Pertuzumab
Anti-HER2 monoclonal antibody
A link here means the marker is often part of considering a drug category, not a recommendation to use it.
Guides discussing this marker
- CLDN18.2-positive gastric cancer: what does the result mean?9 min read
- Understanding clinical trials: terms, phases, and how to check early fit7 min read
- Preparing medical records for a second opinion or clinical trial6 min read
Written to help prepare questions and documents, not to replace a doctor's assessment.
Clinical trials
Studies mentioning this marker
Filtered from public study descriptions. Access status and site readiness remain unverified.
NCT06452277Phase 3Immunotherapy
A Study to Learn More About How Well Sevabertinib Works and How Safe it is Compared With Standard Treatment, in Participants Who Have Advanced Non-small Cell Lung Cancer (NSCLC) With Mutations of the Human Epidermal Growth Factor Receptor 2 (HER2)
Lung Cancer | biomarker: HER2 | Immunotherapy, Chemotherapy
United States, Argentina, Australia +33279 registry sites
Why this appears: Appears because it is recorded for Lung Cancer, it mentions marker HER2, the treatment category is Immunotherapy.
What to verify: Acceptance of patients from outside the local country has not been verified.
- Registry
- Recruiting in registry
- Site
- Not verified
- International access
- Unknown
- Patient match
- Not assessed
Last checked 16 Oktober 2026Source ClinicalTrials.govNCT06452277Not verified
NCT07195695Phase 3Combination regimen
Beamion LUNG-3: Adjuvant Zongertinib vs Standard Treatment in People With Completely Resected Stage II-IIIB NSCLC Harboring Activating HER2 TKD Mutations
Lung Cancer | biomarker: HER2 | Immunotherapy, Targeted therapy
United States, Argentina, Australia +25202 registry sites
Why this appears: Appears because it is recorded for Lung Cancer, it mentions marker HER2, the treatment category is Immunotherapy.
What to verify: Acceptance of patients from outside the local country has not been verified.
- Registry
- Recruiting in registry
- Site
- Not verified
- International access
- Unknown
- Patient match
- Not assessed
Last checked 16 Oktober 2026Source ClinicalTrials.govNCT07195695Not verified
NCT06324357Phase 1 / Phase 2Targeted therapy
Beamion BCGC-1: A Study to Find a Suitable Dose of Zongertinib Used Alone and in Combination With Other Treatments to Test Whether it Helps People With Different Types of HER2+ Cancer That Has Spread
Stomach Cancer | biomarker: HER2 | Targeted therapy
United States, Belgium, China +7103 registry sites
Why this appears: Appears because it is recorded for Stomach Cancer, it mentions marker HER2, the treatment category is Targeted therapy.
What to verify: Acceptance of patients from outside the local country has not been verified.
- Registry
- Recruiting in registry
- Site
- Not verified
- International access
- Unknown
- Patient match
- Not assessed
Last checked 16 Oktober 2026Source ClinicalTrials.govNCT06324357Not verified
NCT06123338Phase 2Combination regimen
A Study of Pembrolizumab With Trastuzumab and Chemotherapy in People With Esophagogastric Cancer
Stomach Cancer | biomarker: HER2 | Immunotherapy, Targeted therapy, Chemotherapy
United States10 registry sites
Why this appears: Appears because it is recorded for Stomach Cancer, it mentions marker HER2, the treatment category is Immunotherapy.
What to verify: Acceptance of patients from outside the local country has not been verified.
- Registry
- Recruiting in registry
- Site
- Not verified
- International access
- Unknown
- Patient match
- Not assessed
Last checked 16 Oktober 2026Source ClinicalTrials.govNCT06123338Not verified
NCT06293898Phase 1Combination regimen
Open Label Study to Evaluate BL-M07D1 in HER2 Expressing Malignant Solid Tumors
Stomach Cancer | biomarker: HER2
United States26 registry sites
Why this appears: Appears because it is recorded for Stomach Cancer, it mentions marker HER2.
What to verify: Acceptance of patients from outside the local country has not been verified.
- Registry
- Recruiting in registry
- Site
- Not verified
- International access
- Unknown
- Patient match
- Not assessed
Last checked 16 Oktober 2026Source ClinicalTrials.govNCT06293898Not verified
NCT05677490Phase 3Immunotherapy
mFOLFIRINOX Versus mFOLFOX With or Without Nivolumab for the Treatment of Advanced, Unresectable, or Metastatic HER2 Negative Esophageal, Gastroesophageal Junction, and Gastric Adenocarcinoma
Stomach Cancer | biomarker: HER2 | Immunotherapy, Chemotherapy
United States, Puerto Rico798 registry sites
Why this appears: Appears because it is recorded for Stomach Cancer, it mentions marker HER2, the treatment category is Immunotherapy.
What to verify: Acceptance of patients from outside the local country has not been verified.
- Registry
- Recruiting in registry
- Site
- Not verified
- International access
- Unknown
- Patient match
- Not assessed
Last checked 16 Oktober 2026Source ClinicalTrials.govNCT05677490Not verified
Check options based on your result
Share the HER2 result you have so we can explain which categories to discuss with a doctor.
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Next steps
These suggestions come from links between entries in TanyaKanker's database, not from a medical judgement. Each suggestion includes why it appears.
Next to learn
- Colorectal Cancer
Cancer type
Reason: Related through a biomarker
- Stomach Cancer
Cancer type
Reason: Related through a biomarker
- Gastric cancer after chemotherapy no longer gives results
Decision situation
Reason: Related through a biomarker
- Newly diagnosed lung cancer
Decision situation
Reason: Related through a biomarker
- HER2 amplification
Molecular alteration
Reason: Related through a biomarker
- HER2-low
Molecular alteration
Reason: Related through a biomarker
To check
- Tumour tissue biopsy
Diagnostic test
Reason: Diperiksa melalui
- Image-guided breast biopsy
Diagnostic test
Reason: Diperiksa melalui
- FISH (fluorescence in situ hybridisation)
Diagnostic test
Reason: Diperiksa melalui
- Immunohistochemistry (IHC)
Diagnostic test
Reason: Diperiksa melalui
- Mammography
Diagnostic test
Reason: Diperiksa melalui
- Next-generation sequencing (NGS)
Diagnostic test
Reason: Diperiksa melalui
What you can do
- Upload medical reports
Build a case summary in twelve steps
Reason: Often the most useful next step after reading this page
- Request a second opinion
Review of the treatment plan
Reason: Relevant when a treatment plan is being considered
- Consult a navigator
A request is recorded with this page context
Reason: For asking the next step directly
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