Definition
- Estrogen and progesterone receptors play a role in hormone-directed transcriptional activation.
- Other names: estrogen receptor assay (ERA), progesterone receptor assay (PGRA), progesterone receptor protein (PRP), estrogen receptor protein (ERP).
- Normal range (ERP, PRP):
- Negative: <5% of nuclei staining
- Borderline: 5 " “19% of nuclei staining
- Positive: 20% of nuclei staining
Use
- To identify patients with breast cancers likely to respond to either additive or ablative hormone therapies
Interpretation (Table 16.30)
‚
TABLE 16 " “30Percentage of Patients Who Respond to Hormone Therapy Based on the Test Results of Estrogen and Progesterone Receptor AssayView LargeTABLE 16 " “30Percentage of Patients Who Respond to Hormone Therapy Based on the Test Results of Estrogen and Progesterone Receptor Assay Percent Response to Hormone Therapy Estrogen Receptor Protein (ERP) Progesterone Receptor Protein (PRP) 75 " “80 Positive Positive 40 " “50 Positive Negative 25 " “30 Negative Positive 10 Negative Negative
Limitations
- Assay is performed on paraffin-embedded, formalin-fixed tissue.
- Receptor status is influenced by age.
- The definition of positive and negative may vary from laboratory to laboratory due to tissue and antibody treatment and antibody specificity.
Suggested Reading
1Ogawa ‚ Y, Moriya ‚ T, Kato ‚ Y Immunohistochemical assessment for estrogen receptor and progesterone receptor status in breast cancer: Analysis for a cut-off point as the predictor for endocrine therapy. Breast Cancer. 2004;11(3):267 " “275.