Human Epidermal Growth Factor Receptor 2 (Her-2) in breast cancer – IHC reporting – GUIDELINES

Human Epidermal Growth Factor Receptor 2 (Her-2) in breast cancer – IHC reporting – GUIDELINES

Publishing Authority: American Society of Clinical Oncology / College of American Pathologists (ASCO / CAP)
Recommendation:

• POSITIVE – IHC 3+ – intense, complete, circumferential membrane staining in > 10% of invasive tumor cells.
• NEGATIVE –  IHC 1+ – incomplete and faint or barely perceptible membrane staining in > 10% of invasive tumor cells.
• NEGATIVE –  IHC 0 – no staining or incomplete and faint or barely perceptible membrane staining and in ≦ 10% of invasive tumor cells.
• EQUIVOCAL – IHC 2+ – incomplete and/or weak/moderate circumferential membrane staining that is >10% of the invasive tumor cells OR complete, intense, circumferential membrane staining in ≦ 10% of invasive tumor cells.

Note: Guidelines on ISH are not included. IHC 2+ / Equivocal must be followed with reflex ISH on same specimen or IHC / ISH on new specimen.
Reference:
1. Wolff AC, Hammond MEH, Hicks DG, Dowsett M, McShane LM, Allison KH et al. Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer: American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Update. J Clin Oncol. 2013 Nov 1;31(31):3997-4013.Pathref accessibility score 4.
2. Wolff AC, Hammond MEH, Hicks DG, Dowsett M, McShane LM, Allison KH et al. Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline Update. Arch Pathol Lab Med. 2014 Feb; 138(2): 241–256.Pathref accessibility score 4.
3. Wolff AC1, Hammond ME, Schwartz JN, Hagerty KL, Allred DC, Cote RJ, Dowsett M, American Society of Clinical Oncology/College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer. J Clin Oncol. 2007 Jan 1;25(1):118-45. Pathref accessibility score 4.
History:
1. The ASCO Clinical Practice Guidelines Committee (CPGC) and the CAP Council on Scientific Affairs (CSA) jointly convened an Expert Panel in 2007 to form guidelines.
2. In 2012,  ASCO and CAP formed an Update Committee to review literature and revise the 2007 guidelines.
3. Simultaneously published in Journal of Clinical Oncology and Archives of Pathology & Laboratory Medicine in 2013.