Pre-Analytical Challenges during RAS Testing: Tissue Quality and the Estimation of Neoplastic Cell Percentage

Dufraing K,Dequeker Emc,Siebers Ag,Lowe K,Van Krieken Jh,Demonty G,Keppens C,Kafatos G

doi:10.36648/2472-1646.5.2.61

Abstract

Laboratories require customized feedback on improving biomarker testing practices. A workshop was organized for laboratories that participated in a European external quality assessment scheme to resolve issues related to the estimation of neoplastic cell percentage and tissue quality for RAS testing for colorectal cancer. An interactive course about tissue quality took place to stress the importance of the pre-analytical phase. During a microscopic session, five H&E stained tumor tissue slides were discussed and neoplastic cell percentages estimated. Participants included 4 pathologists, 3 molecular biologists, a technologist and a clinical geneticist from 7 laboratories. In six laboratories, tumor contents are checked routinely by visual estimation by the pathologist. The average difference between the lowest and highest estimation was 22%. During the workshop the importance of the pre-analytical phase was stressed and feedback was provided. Such initiatives can contribute in improving biomarker testing standards in Europe

Highlights

Since the introduction of precision medicine, where treatmentsCare, Biomedical Quality Assurance Research Unit, University of Leuven, Leuven, Belgium are tailored to specific genetic alterations, clinical decisions rely on accurate test outcomes
Based on the survey results, a description was created on the different pre- and post-analytical steps that are required to be taken by the participating laboratories for determining the neoplastic cell content (Figure 1)
They stated that the neoplastic cell content is always determined by the pathologist as opposed to molecular biologist, technician or clinical scientist in molecular pathology

Summary

Introduction

Since the introduction of precision medicine, where treatments. Biomedical Quality Assurance Research Unit, University of Leuven, Leuven, Belgium are tailored to specific genetic alterations, clinical decisions rely on accurate test outcomes. Correct test outcomes are dependent on both the quality of a test method and the specimen quality (e.g. tissue fixation, tumor size and cellularity, sample type) [2]. This requires harmonization in the pre-analytical phase, which is highly error prone [3,4].

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Conclusion