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Biomarkers
In addition to the standard data items found on a pathology report, information on Biomarkers or Genetics can also be found on the pathology report. Some of these may be found on the original pathology report (with or without an addendum), or in a molecular pathology report.
For Breast, there are several Biomarker data items. These are called Site-Specific Data Items (SSDIs), and are collected for each case.
| Data Item | NAACCR Item # | NAACCR Text Field # |
|---|---|---|
| ER Summary | 3827 | 2570: Text-Dx Proc Path |
| ER Percent Positive | 3826 | 2570: Text-Dx Proc Path |
| PR Summary | 3915 | 2570: Text-Dx Proc Path |
| PR Percent Positive | 3914 | 2570: Text-Dx Proc Path |
| HER2 Overall Summary | 3855 | 2570: Text-Dx Proc Path |
| Ki-67 (MIB-1) | 3863 | 2570: Text-Dx Proc Path |
See Schemas | SSDI and Grade Data
for the SSDI manual and the schema information or SEER*RSA in the Breast schema for complete coding instructions for these data items.
Note: For the SSDIs, it is very important that you read the general instructions (see NAACCR link above) first. For example, the general instructions tell you how to code when there is a range, when “less than” or “greater than” is used. After the general instructions are reviewed, you move to the data specific instructions.
Biomarkers (tumor markers) can be diagnostic, predictive, and/or prognostic.
- Diagnostic: Aid in making diagnosis
- Predictive: Associated with response to treatment
- Prognostic: Associated with disease outcome (i.e., overall survival)
ER and PR
Estrogen receptor (ER) positivity and progesterone receptor (PR) positivity are favorable prognostic factors in breast cancer, as well as endometrial carcinoma and meningioma. Positive results predict a favorable response to endocrine (hormonal) therapy. Combined ER and PR positivity is associated with increased response to antiestrogen therapies.
The two most common ways to report ER and PR results are the percentage of cells with nuclear positivity (PS) and the average intensity (IS) of staining. Both the PS and IS are based on immunohistochemical staining of tumor cells.
ER Summary [NAACCR Item # 3827] and PR Summary [NAACCR Item # 3826] collect whether the tumor is positive or negative, while ER Percent Positive [NAACCR Item # 3915] and PR Percent Positive [NAACCR Item # 3914] collect the percentage of cells that are positive.
HER2 [NAACCR Item # 3855]
A subset of breast carcinomas (approximately 15% to 20%) overexpress human epidermal growth factor receptor 2 (HER2). The presence of HER2 overexpression in untreated patients is associated with worse prognosis in both node-negative and node-positive patients. Protein overexpression is usually due to HER2 gene amplification. The HER2 protein may also be referred to as ERBB2 and the HER2 gene may also be referred to as the ERBB2 gene. HER2 Overall Summary collects whether the tumor is positive or negative.
Ki-67 [NAACCR Item # 3863]
Ki-67 (MIB-1) is a marker of cell proliferation. A high value indicates a tumor that is proliferating more rapidly. Ki-67 collects the percent positive.
Note: This is also documented as Proliferative Index.
Updated: January 10, 2025