IHC

Estrogen Receptor (ER)

Detects the estrogen receptor, a nuclear hormone receptor expressed in approximately 85% of invasive breast cancers. It serves as a strong predictive marker for response to endocrine therapies such as tamoxifen and aromatase inhibitors and is used to guide hormonal treatment decisions. Even moderate to strong staining in as little as 1% of tumor cells correlates with improved disease-free survival.

Full Description

Detects the estrogen receptor, a nuclear hormone receptor expressed in approximately 85% of invasive breast cancers. It serves as a strong predictive marker for response to endocrine therapies such as tamoxifen and aromatase inhibitors and is used to guide hormonal treatment decisions. Even moderate to strong staining in as little as 1% of tumor cells correlates with improved disease-free survival.

Methodology

IHC

Specimen Requirements

Tissue Block: Formalin-fixed, paraffin-embedded (FFPE) tumor block preferred. Unstained Slides: Recommended 2 charged slides per stain requested (minimum of 1 slide per stain), baked or unbaked. Fixation: Tissue must be fixed in 10% neutral buffered formalin for 6–72 hours.

Storage and Transportation

Use cold pack for transport. Make sure cold pack is not in direct contact with specimen.

Turnaround Time

Global: 48 Hrs, Image Analysis (tech-only): 36 Hrs, Tech-Only (stain only): 24 Hrs

CPT Codes

88342x1 or 88341x1; 88361x1; 88360x1