K Goto1, M Satouchi2, G Ishii3, K Nishio4, K Hagiwara5, T Mitsudomi6, J Whiteley7, E Donald7, R McCormack7, T Todo8. 1. Division of Thoracic Oncology, National Cancer Center Hospital East, Chiba. Electronic address: kgoto@east.ncc.go.jp. 2. Department of Thoracic Oncology, Hyogo Cancer Center, Hyogo. 3. Pathology Division, Innovative Medical Research Center, National Cancer Center Hospital East, Chiba. 4. Department of Genome Biology, Kinki University School of Medicine, Osaka. 5. Department of Respiratory Medicine, Saitama Medical University, Saitama. 6. Department of Thoracic Surgery, Aichi Cancer Center Hospital, Aichi, Japan. 7. Department of Personalised Healthcare and Biomarkers, AstraZeneca Pharmaceuticals, Macclesfield, UK. 8. Department of Research and Development, AstraZeneca KK, Osaka, Japan.
Abstract
BACKGROUND: Epidermal growth factor receptor (EGFR) mutation is predictive for the efficacy of EGFR tyrosine kinase inhibitors in advanced non-small-cell lung cancer (NSCLC) treatment. We evaluated the performance, sensitivity, and concordance between five EGFR tests. MATERIALS AND METHODS: DNA admixtures (n = 34; 1%-50% mutant plasmid DNA) and samples from NSCLC patients [116 formalin-fixed paraffin-embedded (FFPE) tissue, 29 matched bronchofiberscopic brushing (BB) cytology, and 20 additional pleural effusion (PE) cytology samples] were analyzed. EGFR mutation tests were PCR-Invader, peptide nucleic acid-locked nucleic acid PCR clamp, direct sequencing, Cycleave, and Scorpion Amplification Refractory Mutation System (ARMS). Analysis success, mutation status, and concordance rates were assessed. RESULTS: All tests except direct sequencing detected four mutation types at ≥1% mutant DNA. Analysis success rates were 91.4%-100% (FFPE) and 100% (BB and PE cytology), respectively. Inter-assay concordance rates of successfully analyzed samples were 94.3%-100% (FFPE; kappa coefficients: 0.88-1.00), 93.1%-100% (BB cytology; 0.86-1.00), and 85.0%-100% (PE cytology; 0.70-1.00), and 93.1%-96.6% (0.86-0.93) between BB cytology and matched FFPE. CONCLUSIONS: All EGFR assays carried out comparably in the analysis of FFPE and cytology samples. Cytology-derived DNA is a viable alternative to FFPE samples for analyzing EGFR mutations.
BACKGROUND:Epidermal growth factor receptor (EGFR) mutation is predictive for the efficacy of EGFR tyrosine kinase inhibitors in advanced non-small-cell lung cancer (NSCLC) treatment. We evaluated the performance, sensitivity, and concordance between five EGFR tests. MATERIALS AND METHODS: DNA admixtures (n = 34; 1%-50% mutant plasmid DNA) and samples from NSCLCpatients [116 formalin-fixed paraffin-embedded (FFPE) tissue, 29 matched bronchofiberscopic brushing (BB) cytology, and 20 additional pleural effusion (PE) cytology samples] were analyzed. EGFR mutation tests were PCR-Invader, peptide nucleic acid-locked nucleic acid PCR clamp, direct sequencing, Cycleave, and Scorpion Amplification Refractory Mutation System (ARMS). Analysis success, mutation status, and concordance rates were assessed. RESULTS: All tests except direct sequencing detected four mutation types at ≥1% mutant DNA. Analysis success rates were 91.4%-100% (FFPE) and 100% (BB and PE cytology), respectively. Inter-assay concordance rates of successfully analyzed samples were 94.3%-100% (FFPE; kappa coefficients: 0.88-1.00), 93.1%-100% (BB cytology; 0.86-1.00), and 85.0%-100% (PE cytology; 0.70-1.00), and 93.1%-96.6% (0.86-0.93) between BB cytology and matched FFPE. CONCLUSIONS: All EGFR assays carried out comparably in the analysis of FFPE and cytology samples. Cytology-derived DNA is a viable alternative to FFPE samples for analyzing EGFR mutations.