Estrogen Receptor

Casandra

Casandra Test Code MP40146Version 1 (DRAFT)

Performing Lab

Lab MPLNLab Test ID I ERCPT Code 88360

Companion Diagnostic

Estrogen Receptor is an FDA-approved companion diagnostic used to help identify patients who may be eligible for targeted therapies.

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Clinical Use

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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.

Test Details

FDA Approved

Companion Diagnostic

Methodology

Immunoassay (IHC)

Biomarkers

Estrogen Receptor

Protein

IHC • Expression • Ordinal Score (e.g., TPS, CPS, H-score)

Result Turnaround Time

2 days

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.