ARUP's Laboratory Test Directory

HercepTest® with Reflex to HER-2/neu by FISH if 2+ or 3+ : 0049172

Mnemonic: HERCE23 IP

Methodology: Immunohistochemistry
Performed: Mon-Fri
Reported: 1-5 days
Reflexed to HER2FISH (0049218) as requested, FISH assay will be performed and reported within 4-12 days, if no repeats are required.
Specimen Required: Collect:  Tumor tissue

Storage/Transport Temperature:  Formalin-fixed, paraffin-embedded tissue block enriched with tumor at 20-25°C. Protect paraffin block from excessive heat. Ship in cooled container during summer months. Include surgical pathology report.

Unacceptable Conditions:  Paraffin block with no tumor tissue remaining and specimens fixed in formalin substitute.

Stability (collection to initiation of testing):  Paraffin block: Ambient: Indefinitely; Refrigerated: Acceptable; Frozen: Unacceptable
Reference Interval:
These results are given as 0 to 3+ with the following definitions and interpretations:
 
Grade Interpretation Microscopic Finding
0 Negative No staining is observed in invasive tumor cells.
1+ Negative Weak, incomplete membrane staining in any proportion of invasive tumor cells, or weak, complete membrane staining in less than 10% of cells.
2+ Equivocal Complete membrane staining that is nonuniform or weak but with obvious circumferential distribution in at least 10% of cells, or intense complete membrane staining in 30% or less of tumor cells.
3+ Positive Uniform intense membrane staining of more than 30% of invasive tumor cells.
3+ reactions with HercepTest® are considered a positive result and indicative of a possible response to Herceptin therapy. 0 and 1+ reactions are considered negative and suggest a lack of response to  Herceptin therapy. It is recommended that a 2+ result be confirmed by FISH testing. FISH results should be considered definitive.

Interpretive Data: The results of the HercepTest® by DAKO are interpreted in a semi-quantitative manner.  Assay is performed on paraffin-embedded, formalin-fixed tissue. Antibody clone is polyclonal and the detection system is LSAB.

ARUP Laboratories uses the ASCO/CAP criteria for interpretation of HER2 protein expression. Positive cases are those with uniform intense membrane staining of more than 30% of invasive tumor cell (Score 3+). Negative cases are defined as no staining (Score 0) or weak, incomplete membrane staining in any proportion of invasive tumor cells, or weak, complete membrane staining in less than 10% of cells (Score 1). Equivocal cases are those with complete membrane staining that is nonuniform or weak but with obvious circumferential distribution in at least 10% of cells, or intense complete membrane staining in 30% or less of tumor cells (Score 2). 

For more information refer to the ASCO/CAP guidelines found at http://www.jco.org 
Note: If HercepTest result is 2+ or 3+, then HER-2/neu by FISH will be added.
CPT Code(s): 88360, if reflexed add 88368 x2
 
 

 

 

 
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