HER2 Testing (Breast and Gastric Cancer)

HER2 IHC testing: HercepTest™, DAKO anti-Her2/neu 4B5, Ventana® 

HER2 FISH testing: Fluorescence in situ hybridization using the PathyVysion® HER2 DNA Probe Kit (Abbott, CE-IVD).

Clinical Implication

The HercepTest™ anti-Her2/neu 4B5 are suited to detect HER2/neu protein overexpression via immunohistochemistry (IHC) and the PathVysion® HER2 DNA Probe Kit is designed to detect amplification of HER2 via Fluorescence in situ Hybridization in formalin-fixed, paraffin-embedded human breast cancer and gastric cancer tissue specimens. Detection of HER2 overexpression confirmed by amplification of HER2 is indicated as an aid in the assessment of breast cancer or gastric cancer patients for whom HERCEPTIN® (trastuzumab) is being considered (1,2,3).

Specimen Requirements

Acceptable specimens for HER2 testing include formalin-fixed paraffin-embedded tissues with a fixation time of 6-48 hours. For breast cancer specimens, fixation up to 72 hours is acceptable (2). 

Volume

1 representative paraffin block is preferred. Alternatively, 5 unstained freshly sectioned tissue sections are accepted (1 slide of 4 or 5 µm thickness for H&E staining, a minimum of 4 slides of 4-5 µm thickness for HER2 testing).

Storage and Shipment Instructions

Maintain and ship specimens at ambient temperature.

Limitations

Fixatives other than formalin (e.g. fixatives containing picric acid), fixations times less than 6 hours or exceeding 72 hours or exposure to severe heath or chemicals may give rise to inadequate results.

Special Requirements

If HER2 IHC has been tested elsewhere, please include the HER2 IHC slide in the shipment or indicate the HER2 IHC status on the Oncology Request Form. If shipped, the IHC slide will be returned together with the results.

Turn-Around Time

HER2 IHC: 5 business days.

HER2 FISH: 10 business days.

References

  1. Wolff AC et al. American Society of Clinical Oncology/College of American Pathologists guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer.J Clin Oncol. 2007;25(1):118-45.
  2. Wolff AC et al. Recommendations for Human Epidermal Growth Factor Receptor 2 Testing in Breast Cancer. American Society of Clinical Oncology/College of American Pathologists Clinical Practice Guideline update. J Clin Oncol. 2013;31(31):3997-4013.
  3. Results of ToGa Trial: Van Cutsem E, Kang Y, Chung H, Sawaki A, Lordick F, Hill J, Lehle M, Feyereislova A, Bang Y (2009) Efficacy results from the ToGA trial: A phase III study of trastuzumab added to standard chemotherapy (CT) in first-line human epidermal growth factor receptor 2 (HER2)-positive advanced gastric cancer (GC). J Clin Oncol 27:18 s (suppl; abstr LBA4509) ASCO