HER2 Amplification Associated with Gastroesophageal Cancer, FISH, Tissue
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
To guide therapy for patients with gastroesophageal cancer, as patients with HER2 amplification may be candidates for Herceptin therapy
To confirm the presence of HER2 amplification in cases with 2+ (low-level) or 3+ (high-level) HER2 protein overexpression by immunohistochemistry
Fluorescence In Situ Hybridization (FISH)
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
HER2 Amp, Gastroesophageal FISH
c-erb-b2 Amplification Test
FISH with HER-2/neu Gene
FISH, HER-2/neu Amp.
GE Junction Cancer
HER-2/neu Amplification Test (FISH)
FISH with HER-2/neu Gene
FISH, HER-2/neu Amp.
GE Junction Cancer
HER-2/neu Amplification Test (FISH)
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Provide a pathology report with each tissue specimen. The pathology report must include type of fixation used (ie, >6 hours and <48 hours). The laboratory will not reject a specimen that arrives without this information but will hold analysis of the specimen until a pathology report is received.
Specimen Type: Tissue block
Collection Instructions: Submit formalin-fixed, paraffin-embedded gastroesophageal cancer tissue.
Forms: If not ordering electronically, submit a Cytogenetics Hematologic Disorders Request Form (Supply T607) with the specimen.
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
Gastroesophageal cancer is the fourth most commonly diagnosed cancer. To date, chemotherapy for gastroesophageal cancer is often ineffective and its prognosis remains poor. Recent studies suggest that the HER2 oncogene can be used as a marker to identify aggressive disease.
In much the same way as was demonstrated for HER2-positive breast cancer, the HER2 gene status in gastroesophageal cancers can be used to determine treatment approaches. Amplification of the HER2 gene and overexpression of the HER2 protein have been associated with a shorter disease-free survival and shorter overall survival in gastric and gastric-esophageal junction cancers. Patients whose tumors demonstrate HER2 amplification may be candidates for treatment with Herceptin (trastuzumab).
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretative report will be provided.
An interpretive report is provided. Results are interpreted utilizing the 2007 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines for breast tumors, and the guidelines used by the ToGA trial.(1)
The degree of HER2 amplification varies in tumors. Some exhibit high levels of amplification (HER2:CEP17 ratio >4.0), whereas others exhibit low-level amplification (HER2:CEP17 ratio of 2.2-4.0). It is not currently known if patients with different levels of amplification have the same prognosis and response to therapy.
Reports also interpret the HER2 copy number changes relative to chromosome 17 copy number (aneusomy) or potential structural changes that increase HER2 copy number.
Rare cases may not show HER2 amplification but still have HER2 protein overexpression demonstrated by immunohistochemistry. The clinical significance of HER2 protein overexpression in the absence of HER2 gene amplification is unclear. However, these patients may have a worse prognosis and be candidates for Herceptin treatment.
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is only for primary or metastatic gastroesophageal tumors. For breast tumors, order #81954 HER2 Amplification Associated with Breast Cancer, FISH, Tissue, for other tumor types, order #60655 HER2 Amplification, Miscellaneous Tumor, FISH, Tissue.
This indication for the HER2 FISH test is not approved by the FDA and should be used as an adjunct to existing clinical and pathologic information.
The assay has been optimized for formalin-fixed, paraffin-embedded tissue specimens. Optimum fixation should be between 6 and 48 hours in 10% neutral buffered formalin. Other types of fixatives should not be used.
The prognostic information provided by the HER2 status of a patient's tumor should not be interpreted in isolation because other prognostic features (eg, lymph node status, tumor size) may be of equal or greater importance in determining the patient's prognosis.
Retrospective data was reviewed on 85 gastroesophageal tumors using the PathVysion HER2 probe set. The FISH results were compared to immunohistochemistry (IHC) testing. Of 36 specimens with HER2 amplification (ratio >2.2), 20 were 3+ by IHC, 8 were 2+, 1 was 1+, and 7 had unknown IHC results. Twenty-five normal gastric tissue control specimens were also tested. The correlation of FISH and IHC results are similar to those observed in validation studies for breast tumor specimens, so the interpretative guidelines will be the same.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Bang YJ, Van Cutsem E, Feyereislova A, ToGA Trial Investigators: Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastro-oesophageal junction cancer (ToGA): a phase 3, open-label, randomised controlled trial. Lancet 2010 Sep 3;376(9742):687-697
2. Hofmann M, Stoss O, Shi, D, Buttner R, et al: Assessment of a HER2 scoring system for gastric cancer: results from a validation study. Histopathology 2008;52:797-805
3. Reichelt U, Duesedau P, Tsourlakis M, et al: Frequent homogeneous HER-2 amplification in primary and metastatic adenocarcinoma of the esophagus. Mod Pathol 2007;20:120-129
Method Description Describes how the test is performed and provides a method-specific reference
The test uses the dual-color PathVysion HER2 DNA probe set (Abbott Molecular) with a HER2 probe and a chromosome 17 centromere probe (CEP17; D17Z1). Paraffin-embedded tissues are cut at 5 microns and mounted on positively charged glass slides. Four slides are prepared, with 1 slide stained with hematoxylin and eosin (H and E). The selection of tissue and the identification of target areas on the H and E-stained slide is performed by a pathologist. Using the H and E slide as a reference, target areas are etched with a diamond-tipped etcher on the back of the unstained slide to be assayed. The probe set is hybridized to the appropriate target areas and 2 technologists analyze 30 interphase nuclei each (60 total) with the results expressed as the average ratio of HER2 signals as compared to D17Z1 signals. A HER2:CEP17 ratio >2.2 indicates HER2 amplification, a HER2:CEP17 ratio of 1.8 to 2.2 is considered equivocal, and HER2:CEP17 ratio of <1.8 is considered not amplified. (Unpublished Mayo method)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CST.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test has been modified from the manufacturer’s instructions. Its performance characteristics were determined by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
88271 x 2-Molecular cytogenetics (eg, FISH), each probe
88274-Interphase in situ hybridization
88291-Cytogenetics and molecular cytogenetics, interpretation and report
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|51120||Order Date||In Process|
|CG555||Reason for Referral||42349-1|
|51128||Release Date||In Process|