The relevance of external quality assessment for molecular testing for ALK positive non-small cell lung cancer: results from two pilot rounds show room for optimization.
OBJECTIVE
Molecular profiling should be performed on all advanced non-small cell lung cancer with non-squamous histology to allow treatment selection. Currently, this should include EGFR mutation testing and testing for ALK rearrangements. ROS1 is another emerging target. ALK rearrangement status is a critical biomarker to predict response to tyrosine kinase inhibitors such as crizotinib. To promote high quality testing in non-small cell lung cancer, the European Society of Pathology has introduced an external quality assessment scheme. This article summarizes the results of the first two pilot rounds organized in 2012-2013.


METHODS
Tissue microarray slides consisting of cell-lines and resection specimens were distributed with the request for routine ALK testing using IHC or FISH. Participation in ALK FISH testing included the interpretation of four digital FISH images.


RESULTS
Data from 173 different laboratories was obtained. Results demonstrate decreased error rates in the second round for both ALK FISH and ALK IHC, although the error rates were still high and the need for external quality assessment in laboratories performing ALK testing is evident. Error rates obtained by FISH were lower than by IHC. The lowest error rates were observed for the interpretation of digital FISH images.


CONCLUSIONS
There was a large variety in FISH enumeration practices. Based on the results from this study, recommendations for the methodology, analysis, interpretation and result reporting were issued. External quality assessment is a crucial element to improve the quality of molecular testing.
Department of Public Health and Primary Care, Biomedical Quality Assurance Research Unit, KU Leuven - University of Leuven, Leuven, Belgium.
Lien
L
Tembuyser
Department of Public Health and Primary Care, Biomedical Quality Assurance Research Unit, KU Leuven - University of Leuven, Leuven, Belgium.
Véronique
V
Tack
Department of Pathology, Antwerp University Hospital, Edegem, Belgium.
Karen
K
Zwaenepoel
Department of Pathology, Antwerp University Hospital, Edegem, Belgium.
Patrick
P
Pauwels
UK NEQAS ICC & ISH, London, United Kingdom.
Keith
K
Miller
Institute for Pathology, Basel University Hospital, Basel, Switzerland.
Lukas
L
Bubendorf
Department of Pathology, Aberdeen Royal Infirmary, Aberdeen, United Kingdom.
Keith
K
Kerr
Department of Pathology and Medical Biology, University of Groningen, Groningen, the Netherlands.
Ed
E
Schuuring
Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands.
Erik
E
Thunnissen
Department of Public Health and Primary Care, Biomedical Quality Assurance Research Unit, KU Leuven - University of Leuven, Leuven, Belgium.
Elisabeth M C
EM
Dequeker
D000077548:Anaplastic Lymphoma Kinase; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D066246:ErbB Receptors / Q000235:genetics; D015321:Gene Rearrangement; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000592:standards*; D007753:Laboratories / Q000592:standards*; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000235:genetics / Q000473:pathology; D011785:Quality Assurance, Health Care; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics*
C000626173:ALK protein, human; D000077548:Anaplastic Lymphoma Kinase; D066246:ErbB Receptors; D020794:Receptor Protein-Tyrosine Kinases