Download Breast Cancer: FISH for ERBB2 (HER2)

Breast Cancer: FISH for ERBB2 (HER2)
Test Purpose
Detection of ERBB2 (HER2) genomic amplifications.
Background
Information
Breast cancer is a heterogeneous disease and the current challenges are to find
prognostic and predictive marker to assist in clinical management.
Proteins on the tumour surface used for targeted therapies have shown clinical
benefits. Amplification and over-expression of the ERBB2 (HER2) oncogene occurs
in 20-30% of invasive breast carcinomas.
ERBB2 (HER2) amplification is
associated with poor prognosis however they are likely to respond to certain
chemotherapeutic regimes.
Furthermore, these patients appear to respond
favorably with the humanized monoclonal antibody Herceptin, either as a single
agent or in combination.
Clinical
Indications
ERBB2 (HER2) FISH analysis is specifically offered as a prognostic marker for
invasive breast cancer and for those patients whom therapy for the humanized
monoclonal antibody Herceptin is contemplated. The results should be interpreted
in context with other genetic, pathological, and clinical information.
Principle of
Test
DNA is labeled with coloured tags that can be seen using a special fluorescence
microscope. This technique is called Fluorescence In Situ Hybridization (FISH).
Specimen
Requirements
Formalin Fixed Paraffin Embedded (FFPE) tissue:
The laboratory requires 6 x unstained slides from 4 micron sections on polylysine
coated slides. At least 30 malignant cells must be available for analysis.
Slides must have 2 forms of ID: a laboratory number and a name or NHI.
A Referral Form should be completed and a histology report enclosed to assist in
the interpretation of the result.
Result
Interpretation
Not amplified is where ratio < 1.8
Equivocal is where ratio is equal to or between 1.8 and 2.2
Amplified is where ratio is > 2.2
Polysomy should be interpreted with caution.
Representative
Image
No Amplification of
ERBB2
Amplification of
ERBB2
R=ERBB2
G=17cen control
R=ERBB2
G=17cen control
Limitations
This technique examines anomalies that are at the defined locus and will not
detect other anomalies. Very small rearrangements or point mutations will not be
detected by this method.
Extra Tests
FFPE 008.1 Breast+EGFR, FFPE 008.2 Breast+TOP2A
References
Seidman AD, Fomier NM, Esteva FJ, et al. Weekly Trastauzumab and Piclitaxel
therapy for metastatic breast cancer with analysis of efficacy by HER-2
immunophenotype and gene amplification. J Clin Oncol,19(10),2587-2595,2001
Slamon DJ, Leyland-Jones B, Shak S, et al. Use of chemotherapy plus monoclonal
antibody against HER-2 for metastatic breast cancer that over-expresses HER-2. N
Engl J Med, 344,783-792,2001
Billing Code
FFPE 008.0 Breast
IGENZ Ltd, Level 2, Quay Park Health, 68-70 Beach Rd, Auckland CBD, New Zealand
Phone +64 9 307 3981 Fax +64 9 307 3983 www.igenz.co.nz
IGENZ Ltd, Level 2, Quay Park Health, 68-70 Beach Rd, Auckland CBD, New Zealand
2007 Breast HER2 Info
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