FISH ANALYSIS HER-2/NEU (PATHVYSION HER-2) BREAST CANCER

General Information

HLAB/HOL Code: FISH
UPHSM LIS Test #: 4324
Schedule: Monday - Friday
Testing Time: 1 - 3 days
Testing Lab: UP Health System-Marquette

Specimen Info
Only 1 specimen type required, unless otherwise specified

Volume:
Temperature: Ambient
Tube Type: Formalin-Fixed, Paraffin-embedded Tumor Tissue
Collection Info:
Upon collection the specimen must be placed immediately 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 utilized. Prepare specimen in paraffin embedded tissue block. Maintain the specimen at room temperature. DO NOT FREEZE.

Fixation guidelines:
1. Specimens should be immersed in fixative within 1 hour of the biopsy or resection procedure.
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 the laboratory

Unacceptable Conditions:
     A. Tissue not verified for presence of invasive carcinoma.
     B. Specimen fixed in fixative other than 10% neutral buffered formalin.
     C. Decalcified tissues.

Please Provide:
(1) Pathology Report
(2) H & E of the fixed specimen. Region of invasive carcinoma marked by a pathologist on the H & E.

Methods

Fluorescent In situ Hybridization (FISH) of 5 um cut tissue slide. Processing of tissue and analysis of 60 cells. Probes specific for HER-2/neu locus and CEP 17 are hybridized. CEP 17 is included as the control which will detect aneusomy of Chromosome 17.

Clinical Utilities

Detection of amplification of the HER2 gene associated with invasive breast cancer and gastroesophageal adenocarcinoma. The detection of the presence of HER-2 gene amplification is based on counting fluorescent HER-2/neu signals and CEP 17 signals contained within the 60 interphase nuclei of invasive carcinoma cells. HER-2/nue FISH detection is indicated as an aid in the assessment of patients for whom HERCEPTIN (Trastuzumab) treatment is being considered.

CPT Codes

88271x2, 88274x1, 88291x1

* The CPT codes provided are based on AMA guidelines and are for informational purposes only. CPT coding
is the sole responsibility of the billing party. Please direct any questions regarding coding to the payer being billed.

Reference Range

Must report HER2 test result as POSITIVE for HER2 gene amplification if:
• Dual-probe HER2/CEP 17 ratio is ≥ 2.0 with an average HER2 copy number ≥ 4.0 signals per cell.
• Dual-probe HER2/CEP 17 ratio is ≥ 2.0 with an average HER2 copy number < 4.0 signals per cell.
• Dual-probe HER2/CEP 17 ratio is < 2.0 with an average HER2 copy number ≥ 6.0 signals per cell.

Must report HER2 test result as EQUIVOCAL and order reflex test (either same specimen with alternative test or new specimen same testing method) for HER2 gene amplification if:
• Dual-probe HER2/CEP 17 ratio is < 2.0 with an average HER2 copy number ≥ 4.0 and <6.0 signals per cell.

Must report HER2 test result as NEGATIVE for HER2 gene amplification if:
• Dual-probe HER2/CEP 17 ratio is < 2.0 with an average HER2 copy number < 4.0 signals per cell.

Must report HER2 test result as INDETERMINATE for HER2 gene amplification if:
• Technical issues prevent the result from being reported as positive, negative or equivocal.  Such conditions include inadequate specimen handling, artifact that make it difficult to interpret and analytic testing failure.

An interpretive report will be provided.