HER2

HER2 (Human Epidermal growth factor Receptor 2) is a protein found on the surface of cells that signals them to grow and divide. When tumors make too much HER2 or carry extra copies of the HER2 gene, the cancer often grows faster, but these tumors may also respond to drugs specifically designed to block HER2.

Origin

HER2 was identified in the early 1980s by researchers including Robert Weinberg's group at MIT, who found a related gene (neu) in rat tumors. It was later recognized as the human equivalent of the ERBB2 gene and named the second member of the HER (human epidermal growth factor receptor) family. HER2-targeted therapy became a landmark of precision oncology with the approval of trastuzumab (Herceptin) for breast cancer in 1998.

Significance in Asbestos Context

HER2 is most commonly tested in breast and gastric cancers, but it is also evaluated in some lung cancers, which matters to asbestos-exposed patients diagnosed with non-small cell lung cancer. If your tumor is HER2-positive or carries a HER2 mutation, you may qualify for targeted drugs (such as trastuzumab deruxtecan) that can work when standard chemotherapy fails. HER2 status does not change whether asbestos caused your cancer. Causation is established through your exposure history and the Helsinki Criteria, but it can affect prognosis and the treatment options your oncologist discusses. HER2 is not a standard marker for mesothelioma, so for that diagnosis the more relevant molecular tests are BAP1, MTAP, and CDKN2A.

Example Sentence

After her lung cancer biopsy, the oncologist ordered HER2 testing along with EGFR and ALK to see whether any targeted therapies might be appropriate alongside the standard treatment plan for her asbestos-related disease.

Related Terms

Biomarker, EGFR, Targeted Therapy, Non-Small Cell Lung Cancer, Immunohistochemistry, Molecular Profiling

Notes

• If you have been diagnosed with lung cancer, ask your oncologist whether comprehensive molecular profiling (including HER2, EGFR, ALK, ROS1, KRAS, and PD-L1) has been performed on your tumor tissue.
• Request copies of all pathology and molecular testing reports for your records. These documents are important both for treatment decisions and for documenting your diagnosis in a legal claim.
• HER2 testing is usually done by immunohistochemistry (IHC) and/or FISH; ask which method was used and what the result was (0, 1+, 2+, or 3+, or gene amplification status).
• HER2-directed therapies for lung cancer are a relatively recent development, so ask whether your treatment center participates in clinical trials if your tumor is HER2-altered.
• Preserve any remaining tumor tissue blocks at the pathology lab; additional testing may be needed later as new targeted therapies become available.