• Test Code:
  • Department:
    Cancer FISH
  • Test Synonyms:
    HER2HER-2/neuERBB2 (17q12-q12)
  • CPT Code(s):

The PathVysion HER-2/neu probe set is designed to detect amplification of the HER-2/neu gene by fluorescent in situ hybridization (FISH) in formalin-fixed, paraffin-embedded (FFPE) human breast and gastric cancer tissue specimens.

For breast cancer indication, results from the PathVysion FISH assay are intended for use as an adjunct to existing clinical and pathologic information currently used as prognostic factors in stage II, node-positive breast cancer patients.  Results of the PathVysion FISH assay may aid in predicting disease-free and overall survival in patients, as well as direct appropriate therapy.


FISH is performed on deparaffinized sections of FFPE tumor tissue using the PathVysion probe set.   Slides are prepared per standard protocols and at least 25 interphase cells are scored for number of HER-2 signals relative to the number of chromosome 17 centromere signals.  Additional cells may be scored according to guidelines below.

ASCO/CAP Guideline Focused Update 2018

Specimen Requirements:

Formalin-fixed paraffin-embedded tumor block or FFPE slides**

  • Preferred slice thickness is 4-5 microns on positively charged slides. 
  • Please submit 3-5 slides.  Store at room temperature.
  • Contact Client Services at (855) 535-1522 for more information.

**ASCO/CAP guidelines recommend a time to fixation of less than 1 hour and a fixation time in 10% neutral buffered formalin of 6-72 hours.  Testing on specimens fixed for less than 6 hours is not acceptable per CAP guidelines, as they are deemed “Estrogen Receptor Uninterpretable”.

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES.  Please include detailed clinical information.

Test Performed (Days):


Turn Around Time:

3-7 days

Shipment Sensitivity Requirements:

  • Ship via overnight express, using the FedEx priority overnight label provided. 
  • Contact Client Services at (855) 535-1522 for shipping kits and instructions.


  1. ASCO/CAP Guideline Focused Update 2018 (Wolff et al. 2018; ASCO/CASP HER2 Testing in Breast Cancer Update, Arch Pathol Lab Med doi: 10.5858/arpa.2018-0902-SA)

Additional Info: