HER2 IHC Summary


**Note 1:** Physician statement of HER2 IHC Summary can be used to code this data item when no other information is available. **Note 2:** The HER2 IHC test performed on the primary breast tissue is to be recorded in this data item. **Note 3:** Results from nodal or metastatic tissue may be used, ONLY when there is no evidence of primary tumor. **Note 4:** In cases where HER2 IHC is reported on more than one breast tumor specimen, record the highest value. If any sample is positive, record as positive. **Note 5:** If neoadjuvant therapy is given, record the assay from tumor specimens prior to neoadjuvant therapy. * If neoadjuvant therapy is given and there are no HER2 IHC results from pre-treatment specimens, report the findings from post-treatment specimens. **Note 6:** If HER2 IHC is positive on an in situ specimen and HER2 IHC is negative on all tested invasive specimens, code HER2 IHC as negative (code 0). **Note 7:** A 2+ (equivocal) finding by IHC should result in additional testing with ISH to determine gene copy number. **Note 8:** An immunohistochemistry (IHC) test identifies the protein expressed by the gene (ERBB2), and an in situ hybridization (ISH) test identifies the number of copies of the gene (ERBB2) itself.




NAACCR #3850


Code Description
0 Negative (Score 0)
1 Negative (Score 1+)
2 Equivocal (Score 2+) Stated as equivocal
3 Positive (Score 3+) Stated as positive
4 Stated as negative, but score not stated
7 Test ordered, results not in chart
8 Not applicable: Information not collected for this case (If this item is required by your standard setter, use of code 8 will result in an edit error.)
9 Not documented in medical record Cannot be determined (indeterminate) HER2 IHC Summary not assessed or unknown if assessed