Solid Tumors

Amplification of the ERBB2 gene (encoding for HER2 protein) is detected by fluorescent in
situ hybridization (FISH) in human breast and esophagogastric cancer tissue specimens.

disease state indication(s)
Breast Cancer, Gastric Cancer, Esophageal Cancer

clinical use
Predictive, Prognostic
ERBB2 gene amplification determines eligibility for targeted anti-HER2 therapies (such as
trastuzumab). In breast cancer, HER2-positivity is associated with a poor prognosis.

methodology/product platform
Fluorescence in situ hybridization (FISH)

specimen type and requirements
Preferred: One (1) or two (2) formalin-fixed, paraffin-embedded (FFPE) blocks containing
tumor tissue from the most recent surgery or biopsy. For breast cancer cases, if HER2
immunohistochemistry has been previously performed, please send the same block that
was tested as well as the stained IHC slide.

Acceptable Alternative: Two (2) to three (3) unstained FFPE tissue sections recently cut at 4
µm thickness on glass slides, plus accompanying H&E stained slide. For breast cancer
cases, if HER2 immunohistochemistry has been previously performed, please send
unstained slides from the same block that was tested as well as the stained IHC slide.

Unacceptable: Specimens preserved in alternative (non-formalin) fixatives, decalcified
specimens, fresh or frozen tissue.

Specimens should be fixed in 10% neutral buffered formalin for at least 6 hours and up to
72 hours. The volume of formalin should be at least 10 times the volume of the specimen.
Decalcification solutions with strong acids should not be used.

1. Specimens should be immersed in fixative within one hour of the biopsy or resection
2. If delivery of a resection specimen to the pathology department is delayed (e.g.
specimens from remote sites), the tumor should be bisected prior to immersion in
fixative. In such cases, it is important that the surgeon ensure that the identity of the
resection margins is retained in the bisected specimen; alternatively, the margins may
be separately submitted.
3. The time of removal of the tissue and the time of immersion of the tissue in fixative
should be recorded and submitted to Genoptix.

Note: Use refrigerated cold pack for transport. Make sure cold pack is not in direct contact
with specimen.
DO NOT FREEZE

turnaround time
Tech-only (TC): 3 days
Global (TC & PC): 5 days

cpt code(s)
88377 (x1)

medicare moldx cpt code
Not applicable

regulatory classification
Laboratory developed test (LDT)

ordering option
Global (TC & PC) or Tech-only (TC)