HER2 IHC INTERPRETATION
last update: 08/29/2024
use
imuno histochemistry marker, used to identify aggressive tumors and guide targeted therapy decisions.
NEGATIVE - SCORE 0
COMPLETELY NEGATIVE STAINING.
incomplete faint membrane staining <10% tumor cells
NEGATIVE - SCORE 1+
INcOMPLETE FAINT / BARELY PERCEPTIBLE MEMBRANE STAINING >10% TUMOR CELLS.
EQUIVOCAL - SCORE 2+
COMPLETE BUT WEAK TO MODERATE MEMBRANE STAINING, OBSERVED IN MORE THAN 10% OF TUMOR CELLS. INDICATES COMPLEMENTATION WITH IN SITU HIBRIDIZATION - ISH.
positive - score 3+
COMPLETE, INTENSE, CIRCUNFERENCIAL MEMBRANOUS POSITIVITY IN MORE THA 10% OF TUMOR CELLS.
HER2 LOW
HER2 NEGATIVE - SCORE 1+, OR
HER 2 EQUIVOCAL - SCORE 2+, AND ISH NOT AMPLIFIED.
IMAGES
REFERENCES
Wolff, A. C., Hammond, M. E. H., Allison, K. H., Harvey, B. E., Mangu, P. B., Bartlett, J. M. S., ... & Vance, G. H. (2018). Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Focused Update. Journal of Clinical Oncology, 36(20), 2105-2122.
Penault-Llorca, F., & Viale, G. (2012). Pathological and molecular diagnosis of HER2 status in the breast cancer HER2 status assessment in breast cancer: past, present, and future. Pathobiology, 79(2), 69-78.
Hicks, D. G., & Kulkarni, S. (2008). HER2+ breast cancer: review of biologic relevance and optimal use of diagnostic tools. The American Journal of Clinical Pathology, 129(2), 263-273.
Bartlett, J. M., Starczynski, J., Atkey, N., Kay, E., O'Grady, A., Moore, A., ... & Mulligan, A. M. (2011). HER2 testing in the UK: recommendations for breast and gastric in-situ hybridization methods. Journal of Clinical Pathology, 64(8), 649-653.
Cobleigh, M. A., Vogel, C. L., Tripathy, D., Robert, N. J., Scholl, S., Fehrenbacher, L., ... & Slamon, D. J. (1999). Multinational study of the efficacy and safety of humanized anti-HER2 monoclonal antibody in women who have HER2-overexpressing metastatic breast cancer that has progressed after chemotherapy for metastatic disease. Journal of Clinical Oncology, 17(9), 2639-2648.