Antibody-drug conjugates (ADCs) link an antibody that recognises the tumour to a payload that kills the cell, achieving more precise delivery. Their indication boundaries continue to be updated, which raises a new practical question: patients previously judged to have “no target” may now need their results reinterpreted. This article explains how to verify test results against publicly available indication information.
1. Why a “no target” conclusion may need to be reviewed
In conventional interpretation, HER2 immunohistochemistry of IHC 1+ or 2+ with FISH negative is often classified as HER2 negative. But with the approval of ADCs targeting HER2-low expression, the clinical meaning of such results has changed: the same pathology result may lead to different conclusions at different points in time.
This points to one thing: pathology reports have a shelf life. If the initial diagnosis was made some years ago, it is advisable to reconfirm it against current interpretation criteria.
2. Interpretation criteria for common targets
| Target | Common assay | Key interpretation points |
|---|---|---|
| HER2 | IHC + FISH | IHC 3+ is positive; IHC 1+/2+ requires FISH to determine HER2-low status |
| Claudin 18.2 | IHC | Look at the proportion of positive cells and the staining intensity threshold |
| Other solid tumour targets | NGS / immunohistochemistry | Follow the interpretation criteria stated in the test report |
Specific thresholds are defined by the testing laboratory and the clinical study protocol, and may differ between studies.
3. Pathology re-review and additional staining
If the report you hold is old or incomplete, you can:
- Request a loan of the pathology slides (unstained slides or paraffin blocks) from the original hospital
- Complete additional staining or re-review at a qualified institution
- Submit the new report together with previous reports to the treating physician
4. Pathways to participation in clinical research
Taking part in clinical research is not “free treatment”; it is a medical process with clearly defined conditions:
- Enrolment criteria: stage, number of prior treatment lines, organ function and previous medication history are all screened
- Informed consent: the purpose of the study, possible benefits and risks, and alternative options must be explained in writing
- Follow-up requirements: patients need to return to hospital for scheduled reviews according to the protocol
- Cost boundaries: the investigational drug and study-related tests are usually covered by the sponsor, while other medical costs are still settled as usual
5. Frequently asked questions
Q: Does enrolment guarantee access to the new drug? Not necessarily. Some studies use randomisation or a control design; the protocol is the deciding factor.
Q: Can I apply for several studies at the same time? It is not advisable. Most protocols exclude patients who have recently taken part in another study.
Q: Can the platform guarantee enrolment? No, and it should not promise this. The platform helps to organise pathology and imaging records, contacts institutions with the relevant testing capability, and submits the file to the department running the study. Whether a patient is enrolled is decided by the research team.
Whether a patient is enrolled is decided by the research team according to the protocol criteria. This article does not constitute medical advice or a promise of enrolment.