ERBB2 (HER2/neu) (HercepTest) with Interpretation by Immunohistochemistry, Tissue

Casandra

Casandra Test Code AR98741Version 1 (DRAFT)

Performing Lab

Lab ARUP LaboratoriesLab Test ID 0049174CPT Code 88360

ERBB2 (HER2/neu) (HercepTest) with Interpretation by Immunohistochemistry, Tissue

Also known as: HERCEPIP

Clinical Use

Order Test

Use

The test aids in predicting the response to HER2-directed therapy in patients with breast carcinoma or gastroesophageal adenocarcinoma. It serves as an alternate test to confirm equivocal dual in situ hybridization (ISH) or fluorescence in situ hybridization (FISH) results. The interpretation utilizes specific guidelines and ensures proper processing and evaluation of the tissue sample to provide accurate results.

Special Instructions

Pathology report including tissue source and tumor origin must be submitted. Document time from tissue acquisition to fixation and fixation duration on the requisition or at the time of order. If multiple specimens are submitted, clarify the selection process or provide individual orders for each sample.

Limitations

The predictive value of HER2 expression, if detected, is uncertain in tumors other than breast and gastric. The test relies on formalin-fixed, paraffin-embedded tissue stained using the proprietary HercepTest methodology. Deviations in tissue processing, such as insufficient fixation time or use of non-standard fixatives, may negatively impact test results. Tissue compliance with ASCO/CAP guidelines is crucial for accurate interpretation.

Test Details

FDA Approved

New York Approved

Methodology

Immunoassay (IHC)

Biomarkers

HER2/neu

Protein

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

LOINC Codes

Result Codes

18474-7
94736-6
31208-2

Result Turnaround Time

1-5 days

Specimen

Tumor Tissue (FFPE)

Volume

Not provided

Minimum Volume

3 slides

Collection Instructions

Formalin fix (10 percent neutral buffered formalin) and paraffin embed within 30 minutes of removal. Transport tissue block or 5 unstained slides in a tissue transport kit.

Storage Instructions

Room temperature or refrigerated. Ship in cooled container during summer months.

Causes for Rejection

Paraffin block with no tumor tissue; fixation delayed more than one hour; non-standard fixative used; tissue fixed for less than 6 hours or more than 72 hours; decalcified specimens.