HER2 status is typically assessed using two main methods: - Immunohistochemistry (IHC): This test detects the presence of HER2 protein on the surface of cancer cells. The results are scored on a scale from 0 to 3+, with 3+ indicating strong overexpression. - Fluorescence In Situ Hybridization (FISH): This test measures the number of copies of the HER2 gene within the cancer cells. A positive result indicates gene amplification. Both tests are crucial for accurate diagnosis and treatment planning.
