2023 World Conference on Lung Cancer (Posters)-EP06.03. Characteristics of Insufficient Samples for EGFR Mutation Testing at the Lung Center of the Philippines

EP06.03. Characteristics of Insufficient Samples for EGFR Mutation Testing at the Lung Center of the Philippines - PDF(Slides)

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This study aimed to describe the characteristics of samples that resulted in "invalid" EGFR mutation tests analyzed at the Lung Center of the Philippines. The availability of quality samples for molecular analysis is a major challenge when assessing EGFR mutation status in advanced NSCLC.<br /><br />A total of 1029 samples were analyzed, with 1004 being valid and 25 being invalid. The invalid samples were categorized into surgical samples (17) and cytology samples (8). Tumor cellularity was also considered, with 5 samples having lower than 10% cellularity, 12 samples having 10% cellularity, and 8 samples having greater than 10% cellularity.<br /><br />All kits used for the EGFR mutation analysis were IVD-marked and met the DNA requirement of 50 ng per reaction/well. The samples were loaded based on manufacturer guidelines, and the Roche Cobas machine provided a code for samples with invalid results related to poor amplifiability of DNA template.<br /><br />Factors that often result in invalid PCR runs include low initial template amount and the presence of contaminants in the dNTP mix. However, cytological sampling did not appear to be the predominant cause of invalid results, as previous studies have shown that 84% of cytological samples were sufficient for EGFR mutation analysis. Tumor cellularity also did not significantly contribute to invalid results, as methods with higher detection sensitivity can detect mutations even at low levels.<br /><br />High-quality samples are crucial for successful analysis and diagnostic purposes. The right method of preservation is important for optimal tissue preservation. The pre-analysis sample preparation, from biopsy to preservation, is crucial for the success or failure of any sample analysis. Continuing to review sample preservation protocols is essential for improving test reliability.<br /><br />In conclusion, understanding the causes of invalid results and improving sample preservation protocols will greatly enhance the reliability of EGFR mutation testing. Analysis should not only focus on testing parameters but also on sample preparation before analysis.

Asset Subtitle

Francisco Heralde, III

Meta Tag

Speaker Francisco Heralde, III

Topic Pathology & Biomarkers: Genetic Biomarkers

Keywords

EGFR mutation tests

Lung Center of the Philippines

samples

invalid results

surgical samples

cytology samples

tumor cellularity

IVD-marked kits

DNA template amplifiability

PCR runs