HER2 status can be determined using various histological techniques:
1. Immunohistochemistry (IHC): This method involves staining the tissue sample with antibodies that bind to the HER2 protein. The intensity of the staining is then evaluated to determine the HER2 status (scored as 0, 1+, 2+, or 3+).
2. Fluorescence In Situ Hybridization (FISH): This technique detects HER2 gene amplification by labeling DNA probes with fluorescent markers. It is used when IHC results are ambiguous (2+).
