Leica Biosystems Bond Oracle HER2 IHC System - Manual (Page 16)

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Leica Biosystems Bond Oracle HER2 IHC System Instructions for Use TA9145 EN-CE-Rev_E 18/06/2013
In conclusion, the data generated in this study demonstrates that the Bond Oracle HER2 IHC
System can be used as an aid in determination of treatment for Herceptin® (trastuzumab)
therapy, based upon its high concordance with the HercepTest.
Clinical Concordance of Bond Oracle HER2 IHC System to PathVysion HER-2
DNA Probe Kit
Part 2 of the study was designed to examine the concordance between the Bond Oracle
HER2 IHC System and the Abbott Molecular PathVysion HER-2 DNA Probe Kit, considered
as the ‘gold standard’ for gene assessment reflex assay used in conjunction with HER-2
immunohistochemistry.
This study was performed at the same investigational sites and used the same study cohort
as in Part 1. All cases were stained with the Abbott Molecular PathVysion HER-2 DNA Probe
Kit according to the manufacturers’ instructions as specified in the package insert. Sequential
sections from each case were stained with the Bond Oracle HER2 IHC System on board a
BOND fully automated, advanced staining system (from Part 1 of the clinical study). Of the 431
cases stained no result was obtained on three occassions due to insufficient probe hybridization
resulting in a total cohort of 428 cases.
All stained slides were scored by trained observers at two investigational sites. For 2x2
concordance analysis the scores were interpreted as negative if the HER2/CEP17 gene
amplification ratio was less than (<) 2.0 and positive if greater than or equal to (>) 2.0 following
a 20 tumor cell count.
2x2 Concordance Results
The observed agreement for 428 samples between the two tests in a 2x2 analysis show a
concordance of 87.6% (375/428) with a 95% CI of 84% to 90%.
The percentage Positive Agreement (sensitivity) or the ability of Bond Oracle HER-2 IHC System
to correctly identify PathVysion positive cases (the percentage of specimens scored positive by
both Bond Oracle HER2 IHC System and PathVysion out of all the PathVysion positive cases)
was 93.8% (61+30/97) with a 95% CI of 86.8% to 97.4%.
The percentage Negative Agreement (specificity) or the ability of the test to correctly identify
PathVysion negative cases (the percentage of specimens scored negative by both Bond Oracle
HER2 IHC System and PathVysion out of all the PathVysion negative cases) was 85.8%
(284/331) with a 95% CI of 81.6% to 89.2%. See Table 8.
PathVysion HER-2 DNA Probe Kit
Negative Positive Totals
Bond Oracle HER2
IHC System 0/1+
284 6 290
2+
41 30 71
3+
6 61 67
Totals
331 97 428
Overall Concordance (95% CI) = 87.6% (84 to 90%)
Table 8. 2x2 concordance of Bond Oracle HER2 IHC System staining v PathVysion HER-2 DNA Probe kit.