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Test ID: FHER2
HER2 Amplification Associated with Breast Cancer, FISH, Tissue

Secondary ID A test code used for billing and in test definitions created prior to November 2011

81954

NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.

Yes

Useful For Suggests clinical disorders or settings where the test may be helpful

As a prognostic indicator for patients with both node-positive or node-negative breast cancer(1)

 

To guide therapy, as patients with HER2 amplification may be candidates for Herceptin therapy(1)

 

To confirm the presence of HER2 amplification in cases with 2+ (low-level) or 3+ (high-level) HER2 overexpression by immunohistochemistry(2,3)

Method Name A short description of the method used to perform the test

Fluorescence In Situ Hybridization (FISH) with DNA Probes

Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name

HER2 Amp, Breast Cancer, FISH

Aliases Lists additional common names for a test, as an aid in searching

Breast Cancer
Breast Carcinoma
c-erb-b2 Amplification Test (FISH)
FISH for Breast Cancer
FISH with HER-2/neu Gene
FISH with HER2/neu Gene
FISH, HER-2/neu Amp.
FISH, HER2/neu Amp
HER-2/neu Amplification Test (FISH)
HER2/neu Amplification Test (FISH)

Specimen Type Describes the specimen type needed for testing

Tissue

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 breast cancer tissue.

Forms: If not ordering electronically, submit a Cytogenetics Hematologic Disorders Request Form (Supply T607) with the specimen.

Reject Due To Identifies specimen types and conditions that may cause the specimen to be rejected

Hemolysis

NA

Lipemia

NA

Icterus

NA

Other

NA

Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.

Specimen TypeTemperatureTime
TissueAmbient (preferred)
 Refrigerated 

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

HER2 (ERBB2: c-erb-b2) is an oncogene on the long arm of chromosome 17 that is amplified in approximately 20% of breast cancers.(1) Amplification or overexpression of HER2 has been shown to be associated with shorter disease-free survival and poorer overall survival in both node-negative and node-positive ductal breast cancers.(1) Patients with HER2 gene amplification or overexpression appear to respond better to cyclophosphamide/doxorubicin/5-fluorouracil (CAF) chemotherapy than patients whose tumors do not exhibit HER2 amplification or overexpression HER2 amplified patients are candidates  for treatment with the drug Herceptin (trastuzumab).(8)

 

FISH with labeled DNA probes to the pericentromeric region of chromosome 17 and to the HER2 locus can be used to determine if a patient's breast cancer has HER2 gene amplification.(2-4) Immunohistochemical analysis is used to determine if a tumor exhibits HER2 overexpression.(1)

 

FISH has been shown to be superior to Southern, Northern, and Western blots and immunohistochemical analyses for the determination of HER2 amplification in formalin-fixed, paraffin-embedded material.(2,3) HER2 amplification as detected with FISH has been shown to be an independent predictor of poor clinical outcome.(5)

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 interpretive report will be provided.

Interpretation Provides information to assist in interpretation of the test results

An interpretive report is provided. Results are interpreted utilizing the 2007 American Society of Clinical Oncology (ASCO)/College of American Pathologists (CAP) guidelines.(6)

 

Specimens with equivocal results (see Method Description) require repeat FISH analysis per ASCA/CAP guidelines.

 

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(2). The clinical significance of HER2 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

The PathVysion HER2 DNA Probe Kit has been optimized for formalin-fixed, paraffin-embedded breast 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, estrogen/progesterone receptor status) may be of equal or greater importance in determining the patient's prognosis.

Supportive Data

Evaluation of amplification of the HER2 gene by FISH in tumors with weakly positive (2+) immunohistochemical staining was performed. A total of 1,556 breast tumor biopsy specimens were referred to Mayo Medical Laboratories, Rochester, MN, for HER2 testing between August and December 2000. Immunohistochemical (IHC) analysis was performed with use of a diagnostic test for the assessment of HER2 overexpression, the Hercep Test. The IHC stained slides were interpreted and scored on a scale ranging from 0 to 3+ according to Food and Drug Administration-approved guidelines. All specimens scored as 2+ were also routinely evaluated by FISH using a HER-2/neu DNA probe kit (PathVysion). Specimens were determined to be amplified if the ratio of HER2 signals to chromosome 17 centromere (CEP17) signals was higher than 2.0. Thirty-eight percent of the specimens evaluated with the HercepTest were scored 0, 35% were 1+, 14% were 2+, and 13% were 3+. Of the 216 tumor specimens scored as 2+, 26 (12%) had a high level of HER2 gene amplification; 54 (25%) demonstrated duplication of HER2; 4 (2%) deleted HER2, CEP17 or both; and 123 (57%) had no apparent HER-2 anomaly, no apparent CEP17 anomaly, nor apparent single gain (aneusomy) of CEP17. The Mayo laboratory was also the reference HER2 testing center for the Intergroup phase III trial that evaluated the use of Herceptin in the adjuvant setter(8). Recent guidelines from the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP), recommend that all specimens with a 2+ HercepTest result be evaluated by FISH for HER2 gene amplification. The results of both assays should be considered before making a decision to recommend anti-HER2 therapy. (7)

 

HER2 Evaluation by IHC

Score 0, 1+

Score 2+

Score 3+

Clinical decision not to treat with anti-HER2 therapy

Reflex to HER2 testing by FISH

Clinical decision for treatment with anti-HER2 therapy

Clinical Reference Provides recommendations for further in-depth reading of a clinical nature

1. Pegram MD, Pauletti G, Slamon DJ: HER-2/neu as a predictive marker of response to breast cancer therapy. Breast Cancer Res Treat 1998;52:65-77

2. Pauletti G, Godolphin W, Press MF, Slamon DJ: Detection and quantitation of HER-2/neu gene amplification in human breast cancer archival material using fluorescence in situ hybridization. Oncogene 1996;13:63-72

3. Press MF, Hung G, Godolphin W, Slamon DJ: Sensitivity of HER-2/neu antibodies in archival tissue specimens: potential source of error in immunohistochemical studies of oncogene expression. Cancer Res 1994;54:2771-2777

4. Masood S, Bui MM, Yung JF, et al: Reproducibility of LSI HER-2/neu SpectrumOrange and CEP 17 SpectrumGreen dual color deoxyribonucleic acid probe kit. For enumeration of gene amplification in paraffin-embedded specimens: a multicenter clinical validation study. Ann Clin Lab Sci 1998;28:215-223

5. Press MF, Bernstein L, Thomas PA, et al: HER-2/neu gene amplification characterized by fluorescence in situ hybridization: poor prognosis in node-negative breast carcinomas. J Clin Oncol 997;15:2894-2904

6. Wolff AC, Hammond ME, Schwartz JN, et al: American Society of Clinical Oncology/College of American Pathologists Guideline recommendations for human epidermal growth factor receptor 2 testing in breast cancer. Arch Pathol Lab Med. 2007 Jan;131(1):18-43

7. Perez EA, Roche PC, Jenkins RB, et al: HER2 testing in patients with breast cancer: poor correlation between weak positively by immunohistochemistry and gene amplification by fluorescence in situ hybridization. Mayo Clin Proc 2002 Feb;77(2):148-154

8. Romond EH, Perez EA, Bryant J, et al: Trastuzumab plus adjuvant chemotherapy for operable HER2-positive breast cancer. N Engl J Med 2005 Oct 20;353(16):1673-1684

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 (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&E). The selection of tissue and the identification of target areas on the H&E stained slide is performed by a pathologist. Using the H&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 normal.(4)

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.

8 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

11 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Indefinitely

Performing Laboratory Location The location of the laboratory that performs the test

Rochester

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 was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

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 IDReporting NameLOINC Code
16878Specimen31208-2
16879Specimen IDN/A
16880SourceN/A
16881Order DateN/A
G_652Reason For Referral42349-1
29636FixativeIn Process
16882MethodIn Process
16884Results31150-6
16885Interpretation69965-2
16886AmendmentIn Process
16887ConsultantN/A
16888Report DateN/A