193P - External quality assessment for ALK immunohistochemistry testing in lung adenocarcinoma within the European Thoracic Oncology Platform Lungscape Pro...
|Date||30 September 2012|
|Event||ESMO Congress 2012|
|Session||Poster presentation II|
Non-Small-Cell Lung Cancer, Metastatic
E. Thunnissen1, K. Kerr2, L. Bubendorf3, D. Nonaka4, F.H. Blackhall5, R. Kammler6, E.J. Speel7, J. De Jong8, M. Martorell9, R.A. Stahel10
The External Quality Assessment (EQA) process in the scope of the Lungscape project of the European Thoracic Oncology Platform (ETOP) aims to detect the prevalence of ALK gene rearrangement in lung adenocarcinoma in Europe. To examine a large set of cases in a multi-institutional collaboration, standard protocols need to be established and tested. The aim of this EQA process was to examine the performance of ALK immunohistochemistry (IHC) in preparation for analysis of cases at each participating site.Material and methods
For ALK immunohistochemistry the antibody clone 5A4 (Novocastra) was selected. Samples generated from cell lines and NSCLC resection specimens were used to construct a tissue microarray (TMA) for internal validation and a different TMA for external validation. Two protocols were established according to the resources available at participating laboratories: one for automated staining and one for a manual bench method. The protocols were validated using control samples by 2 laboratories each. Subsequently, the IHC protocols and TMA were provided to participating laboratories for internal validation. Subsequently external validation was performed using slides from another TMA, containing 5 positive cases and 5 controls. Participants were requested to use a modified (from Ruschoff) H-scoring system when reporting cases, to a maximum score of 200 (moderate/strong staining in 100% of cells).Results
To date 14 labs have participated. 13 labs showed a performance in line with the expected result. The mean H-score out of a maximum of 200 for positive cases was 157 and for negative cases was 5. One of the positive cases was weakly to moderately positive in most labs (mean H-score 119). The remaining lab solved a staining issue and performed well on another TMA.Conclusions
After guided internal validation, the external quality assessment showed excellent technical performance of ALK IHC in NSCLC. The process of EQA ensures uniformity and standardisation across participating laboratories, in preparation for analysis of archival samples for research.Disclosure
All authors have declared no conflicts of interest.