Estrogen Receptor
Companion Diagnostic
Estrogen Receptor is an FDA-approved companion diagnostic used to help identify patients who may be eligible for targeted therapies.
Use
Estrogen receptors (ER), encoded by the ESR1 and ESR2 genes, exist as alpha and beta isoforms. ER alpha is found in luminal epithelial cells, promoting normal development and cell proliferation. In cancerous cells, increased ER activity from overexpression leads to hyperproliferation and tumor formation. ER is a crucial marker for predicting responses to endocrine therapy. High ER levels in tumors correlate with better responses to such treatments.
Special Instructions
Fresh Tissue Biopsies and resections specimens should be immersed in fixative within one hour of the biopsy or resection. The time of immersion in fixative should be recorded and submitted to the laboratory. Total fixation time must be noted for FFPE block or fresh tissue, which is preferred.
Limitations
Specimens must be fixed in 10% NBF or B plus, all other fixatives will be rejected. The test is subject to specific specimen handling conditions as noted in the special instructions. Results may vary based on specimen quality and adherence to proper collection and storage procedures.
FDA ApprovedCompanion Diagnostic
Methodology
Immunoassay (IHC)
Biomarkers
Estrogen Receptor
Protein
Result Turnaround Time
2 days
Related Documents
For more information, please review the documents below
Specimen
Tissue (FFPE)
Volume
Not provided
Minimum Volume
Not provided
Container
FFPE Block
Collection Instructions
Fixative should be at a 20:1 fixative to tissue ratio, 10% neutral buffered formalin for 6-72 hours (48-72 hours PREFERRED). Immersion time should be recorded.
Storage Instructions
Store between 15°C to 25°C.
Causes for Rejection
Specimens fixed in fixatives other than 10% NBF or B plus will be rejected.
Stability Requirements
| Temperature | Period |
|---|---|
| Room Temperature | Indefinite |