HER2 negative means that a cancer cell has a normal amount of the HER2 protein on its surface, indicating the cancer is likely to grow more slowly and be less likely to recur or spread compared to HER2-positive cancers.
Here's a more detailed breakdown:
Understanding HER2
HER2 (Human Epidermal growth factor Receptor 2) is a protein that helps control how cells grow, divide, and repair themselves. It's present in small amounts on the surface of normal cells. However, in some cancers, particularly breast and stomach cancers, the HER2 gene is amplified, leading to an overproduction of the HER2 protein. These cancers are classified as HER2-positive.
What does HER2 negativity signify?
If a cancer is HER2 negative, it means:
- Normal HER2 levels: The cancer cells have a typical amount of the HER2 protein on their surface.
- Less aggressive growth: These cancers tend to grow at a slower rate compared to HER2-positive cancers.
- Lower risk of recurrence and metastasis: HER2-negative cancers are statistically less likely to come back after treatment or spread to other parts of the body.
- Different treatment options: Therapies specifically targeting the HER2 protein (like trastuzumab, also known as Herceptin) are not effective for HER2-negative cancers. Doctors will explore alternative treatment strategies like chemotherapy, hormone therapy, or surgery.
HER2 Testing
The HER2 status of a cancer is determined through laboratory tests performed on a sample of the tumor tissue. Common tests include:
- Immunohistochemistry (IHC): This test uses special antibodies to detect the HER2 protein on the surface of cancer cells. IHC results are typically scored from 0 to 3+. A score of 0 or 1+ is considered HER2 negative.
- Fluorescence in situ hybridization (FISH): This test counts the number of HER2 genes in cancer cells. If the number of HER2 genes is not elevated, the cancer is considered HER2 negative.
Impact on Treatment
HER2 status is a crucial factor in determining the most appropriate treatment plan for cancer. Being HER2 negative typically means that the cancer won't respond to HER2-targeted therapies. Therefore, treatment strategies focus on other pathways and characteristics of the cancer cells to effectively combat the disease.
In summary, HER2 negative indicates a normal level of the HER2 protein on cancer cells, generally associated with slower growth and a lower risk of recurrence, requiring a different approach to treatment compared to HER2-positive cancers.
