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HER2/neu breast cancer by FISH

Test Code


Test Synonyms

HER2/neu, CEP 17,17q11.2q12 amplification


HER2-positive tumors have shown to benefit from Herceptin treatment. Current recommendations for HER2 testing include using FISH as a follow up for all IHC 2+ cases.


Fluorescence in situ Hybridization (FISH)

Turnaround Time

3-5 days

Specimen Requirements

10% neutral buffered formalin fixed paraffin embedded tissue.
5 mm^3 fresh tissue or 3.0 mL (min. 2.0 mL) FNA in MPLN RPMI media

Specimen Stability
Paraffin blocks stable at 18-25°C indefinitely
Fresh tissue or FNA stable at 2-8°C for 72 hours
Storage & Handling

Fresh tissue, FNA or paraffin embedded tissue, ship in a Styrofoam container with a cool/refrigerated pack (Do not allow cool pack to directly contact sample)

Causes for Rejection

Improper specimen labeling; Insufficient sample; Inadequate fixation and/or processing

Reference Range

Specimens with amplification of HER2 show a HER2/CEP17 ratio greater than or equal to 2.0. Non-amplified tissue shows a ratio of less than 2.0.


Her2/neu, also known as erbB2 or HER2, plays a key role in the regulation of cell growth. HER2 is over expressed through gene amplification in 25-30% of breast cancer patients. Over expression of HER2 has also been observed in ovarian, endometrial, gastric and salivary gland carcinomas.

Clinical studies have shown that HER2/neu amplification as demonstrated by FISH is a statistically significant and independent predictor of tumor recurrence when compared to other commonly used prognostic markers such as tumor size, grade, patient age at diagnosis and hormone receptor status.



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