http://jcp.bmj.com/cgi/content/abstract/60/7/816


ORIGINAL ARTICLE
External quality assurance of HER2 fluorescence in situ hybridisation
testing: results of a UK NEQAS pilot scheme
John M S Bartlett1, Merdol Ibrahim2, Keith Miller2, Bharat Jasani3, John M
Morgan3, Ian Ellis4, Elaine Kay5, Hilary Magee6, Sarah Barnett7

1 Endocrine Cancer Group, Edinburgh Cancer Research Centre, Western General
Hospital, Edinburgh, UK
2 UK National External Quality Assessment Scheme, University College London,
London, UK
3 Department of Pathology, School of Medicine, Cardiff University, Cardiff,
UK
4 University of Nottingham, Molecular Medical Sciences, Department of
Histopathology, Nottingham City Hospital, Nottingham, UK
5 Department of Histopathology, Beaumont Hospital and The Royal College of
Surgeons in Ireland, Beaumont Hospital, Dublin, Ireland
6 Adelaide and Meath Hospital, incorporating the National Children's
Hospital, Dublin, Ireland
7 University College London, Advanced Diagnostics, London, UK


Correspondence to:
Dr J M S Bartlett
Endocrine Cancer Group, Edinburgh Cancer Research Centre, Western General
Hospital, Crewe Road South, Edinburgh EH4 2XR, UK; John.Bartlett@...
Background and Aims: Trastuzumab provides clinical benefit for advanced and
early breast cancer patients whose tumours over-express or have gene
amplification of the HER2 oncogene. The UK National External Quality
Assessment Scheme (NEQAS) for immunohistochemical testing was established to
assess and improve the quality of HER2 immunohistochemical testing. However,
until recently, no provision was available for HER2 fluorescence in situ
hybridisation (FISH) testing. A pilot scheme was set up to review the
performance of FISH testing in clinical diagnostic laboratories.

Methods: FISH was performed in 6 reference and 31 participating laboratories
using a cell line panel with known HER2 status.

Results: Using results from reference laboratories as a criterion for
acceptable performance, 60% of all results returned by participants were
appropriate and 78% either appropriate or acceptable. However, 22.4% of
results returned were deemed inappropriate, including 13 cases (4.2%) where
a misdiagnosis would have been made had these been clinical specimens.

Conclusions: The results of three consecutive runs show that both reference
laboratories and a proportion of routine clinical diagnostic (about 25%)
centres can consistently achieve acceptable quality control of HER2 testing.
Data from a significant proportion of participating laboratories show that
further steps are required, including those taken via review of performance
under schemes such as NEQAS, to improve quality of HER2 testing by FISH in
the "real world".



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Abbreviations: FISH, fluorescence in situ hybridisation; NEQAS, National
External Quality Assessment Scheme


Keywords: HER2/erbB-2; FISH/in situ hybridisation; fluorescence; herceptin;
trastuzumab; quality assurance