Human epidermal growth factor receptor-2 (HER2) test result code N

Guide for use:

Record the reported conclusion of the HER2.

If no conclusion is reported use the following guidelines (from the National Breast and Ovarian Cancer Centre and Australian Cancer Network’s pathology reporting guide (3rd ed.) for breast cancer):

CODE 1 Positive

• For in situ hybridisation:
  Result is more than 6 copies of the HER2 gene per nucleus OR a ratio of HER2 gene signals to chromosome 17 signals of more than 2.2.
• For Immunochemistry:
  Result is described as 3+ or +++ OR >30% of cancer cells show strong complete membrane staining without cytoplasmic staining and without staining of normal tissue.

CODE 2 Negative

• For in situ hybridisation:
  Result is less than 4 copies of the HER2 gene per nucleus OR a ratio of HER2 gene signals to chromosome 17 signals of less than 1.8.
• For Immunochemistry:
  Result described as 0, 1+ or + OR <10% of cancer cells show staining.

CODE 3 Equivocal

• For in situ hybridisation:
  Result is an average of between 4 and 6 HER2 gene copies per nucleus with a single probe OR a ratio of HER2 gene signals to chromosome 17 signals in the range of 1.8-2.2.
• For Immunochemistry:
  Result described as 2+ or ++ OR <10% of cancer cells show strong complete membrane staining (rare) OR 10-30% of cancer cells show weak to moderate complete membrane staining OR Strong cytoplasmic staining is present, making assessment of membrane staining difficult.

Supplementary codes

CODE 7 Unknown (test results not available)

Use this code when the test has been performed but the results are not yet available for analysis.

CODE 8 Not applicable (test not done)

This code is used as a validation measure, to show that the reason for the lack of results is due to the test not being performed.