Leica Biosystems HER2 FISH System - 30 Test - Manual (Page 14)

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Page 14 of 24
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Leica Biosystems Leica HER2 FISH System - 30 Test Instructions for Use TA9217 EN-CE-Rev_D 08/04/2013
Unexpected FISH staining, or variations in the staining, may be a result of alterations in the
expression levels of the encoding genes. Any change in expected staining patterns should be
interpreted in association with all other diagnostic investigations. Staining interpretation should
be complemented by morphological studies and the use of suitable control material, and should
be evaluated within the context of the patient’s clinical history and any other diagnostic tests, by
a qualified pathologist.
The performance of the assay (i.e. assessment of adequacy of control materials) and the
interpretation of any staining or its absence must be carried out in an appropriately accredited/
licensed laboratory under the supervision of a suitably qualified and experienced pathologist,
who is responsible for the overall assessment of the in situ hybridization assay and its
interpretation. False positive results in FISH may be due to cross-reactivity of the probe to other
nucleic acid sequences and/or nonspecific binding. Appropriate controls must be employed and
documented, and tests should take into account all relevant expiration dates.
Technical and interpretational variation may also be seen when FISH is utilized on cell line
derived materials (23).
B. Product Specific Limitations
This product is not designed for use in any other DNA-based diagnostic assay.
Do not replace Leica HER2 FISH System - 30 Test reagents with any other components either
supplied by Leica Biosystems or by other manufacturers. To do so will invalidate the assay. The
user must validate any deviation from the recommended procedures.
It is recommended that tissues fixed only in formalin-based fixatives be used in the assay. The
use of any other type of fixative may invalidate the assay.
Tissue sections cut outside of the recommended thickness range have not been validated. The
use of any other section thickness may invalidate the assay.
Clinical Concordance of HER2 FISH System - 30 Test to Abbott
Molecular PathVysion HER-2 DNA Probe Kit
This study examined the suitability of the Leica HER2 FISH System - 30 Test for use as an aid
in determination of treatment for Herceptin (trastuzumab) therapy. The study was designed to
examine the concordance between the Leica HER2 FISH System - 30 Test and a previously
approved diagnostic device, the Abbott Molecular PathVysion HER-2 DNA Probe Kit, considered
as the ‘gold standard’ for this assay. The acceptance criterion for testing was that the lower limit
of the 95% one-sided confidence interval is above 90% between the Leica HER2 FISH System
- 30 Test and the manual Abbott Molecular PathVysion HER-2 DNA Probe Kit, between positive
(amplified) and negative (non-amplified) formalin-fixed, paraffin-embedded (FFPE) invasive
breast cancer cases.
The study was conducted as a three-site, masked evaluation of clinical invasive breast
carcinoma samples. Each of the investigational sites were supplied with archived formalin-fixed,
paraffin-embedded invasive breast carcinoma tissue blocks with known HER2 oncoprotein
expression levels. A cohort of 300 specimens consisting of 75, 0/1+ previously characterized
IHC cases; 150, 2+ previously characterised IHC cases; and 75, 3+ previously characterized
IHC cases were selected, and split equally across each of the three investigational trial sites.
All cases were stained with the manual Abbott Molecular PathVysion HER-2 DNA Probe Kit
Assay according to the manufacturer’s instructions for use, as specified in the package insert.
Sequential sections from each case were then stained with the Leica HER2 FISH System - 30
Test on the Leica BOND-MAX and BOND-III System.
All stained slides were masked and scored in a randomized fashion by a single trained
observer at each of the three investigational trial sites. Scores were interpreted as negative
with a calculated HER2/CEP17 gene ratio of <2.0 and positive with a calculated HER2/CEP17
gene ratio of ≥2.0. Data was then analyzed for concordance, positive staining agreement and
negative staining agreement.