Resumen de Higher Quality of Molecular Testing, an Unfulfilled Priority: Results from External Quality Assessment for KRAS Mutation Testing in Colorectal Cancer
Lien Tembuyser, Marjolijn J. L. Ligtenberg, Nicola Normanno, Sofie Delen, J. Han J. M. van Krieken, Elisabeth M. C. Dequeker
Precision medicine is now a key element in clinical oncology. RAS mutational status is a crucial predictor of responsiveness to anti�epidermal growth factor receptor agents in metastatic colorectal cancer. In an effort to guarantee high-quality testing services in molecular pathology, the European Society of Pathology has been organizing an annual KRAS external quality assessment program since 2009. In 2012, 10 formalin-fixed, paraffin-embedded samples, of which 8 from invasive metastatic colorectal cancer tissue and 2 artificial samples of cell line material, were sent to more than 100 laboratories from 26 countries with a request for routine KRAS testing. Both genotyping and clinical reports were assessed independently. Twenty-seven percent of the participants genotyped at least 1 of 10 samples incorrectly. In total, less than 5% of the distributed specimens were genotyped incorrectly. Genotyping errors consisted of false negatives, false positives, and incorrectly genotyped mutations. Twenty percent of the laboratories reported a technical error for one or more samples. A review of the written reports showed that several essential elements were missing, most notably a clinical interpretation of the test result, the method sensitivity, and the use of a reference sequence. External quality assessment serves as a valuable educational tool in assessing and improving molecular testing quality and is an important asset for monitoring quality assurance upon incorporation of new biomarkers in diagnostic services.
