Kyueng-Whan Min1, Wan-Seop Kim2, Se Jin Jang3, Yoo Duk Choi4, Sunhee Chang5, Soon Hee Jung6, Lucia Kim7, Mee Sook Roh8, Choong Sik Lee9, Jung Weon Shim10, Mi Jin Kim11, Geon Kook Lee12. 1. From the Department of Pathology, Konkuk University School of Medicine, Seoul. 2. From the Department of Pathology, Konkuk University School of Medicine, Seoul, wskim@kuh.ac.kr. 3. Asan Medical Center, University of Ulsan, College of Medicine, Seoul. 4. Chonnam National University Medical School, Gwangju. 5. Inje University College of Medicine, Goyang. 6. Yonsei University Wonju College of Medicine, Wonju. 7. Inha University School of Medicine, Incheon. 8. Dong-A University College of Medicine, Busan. 9. Chungnam National University College of Medicine, Daejeon. 10. Hallym University College of Medicine, Seoul. 11. Yeungnam University College of Medicine, Daegu, and. 12. National Cancer Center, Goyang, Republic of Korea.
Abstract
BACKGROUND: The importance of sensitive methods for the detection of epidermal growth factor receptor (EGFR) mutation is emphasized. The aim of this study is to perform comparative and concordance analyses of direct sequencing, pyrosequencing and peptide nucleic acid (PNA) clamping for detecting EGFR gene mutations using archived tissue and cytology specimens. METHODS: Samples from a total of 112 cases, which were diagnosed with adenocarcinoma of the lung at nine hospitals in Korea were collected. Using the above three methods, the concordance rates of EGFR mutations in exons 18, 19, 20 and 21 were analysed and validated in comparative tissue and cytology specimens. RESULTS: Comparison of EGFR mutation detection between the tissue and cytology had a high concordance rate. The diagnostic performance of pyrosequencing and PNA clamping in tissue was higher than that of direct sequencing as well as cytology. Additionally, among some of the patients who had EGFR wild type by single method, EGFR mutations were detected by other methods. Cytology specimens had a diagnostic performance for the detection of EGFR mutations. CONCLUSIONS: Cytology specimens had a diagnostic performance for the detection of EGFR mutations that was comparable to that of tissues. For detecting EGFR mutations, pyrosequencing or PNA clamping was more sensitive than direct sequencing. In EGFR mutation negative patients who are difficult to obtain tissue, repeating test using pyrosequencing or PNA clamping is recommended to improve the detection rate of EGFR mutation than only one, especially in cytology.
BACKGROUND: The importance of sensitive methods for the detection of epidermal growth factor receptor (EGFR) mutation is emphasized. The aim of this study is to perform comparative and concordance analyses of direct sequencing, pyrosequencing and peptide nucleic acid (PNA) clamping for detecting EGFR gene mutations using archived tissue and cytology specimens. METHODS: Samples from a total of 112 cases, which were diagnosed with adenocarcinoma of the lung at nine hospitals in Korea were collected. Using the above three methods, the concordance rates of EGFR mutations in exons 18, 19, 20 and 21 were analysed and validated in comparative tissue and cytology specimens. RESULTS: Comparison of EGFR mutation detection between the tissue and cytology had a high concordance rate. The diagnostic performance of pyrosequencing and PNA clamping in tissue was higher than that of direct sequencing as well as cytology. Additionally, among some of the patients who had EGFR wild type by single method, EGFR mutations were detected by other methods. Cytology specimens had a diagnostic performance for the detection of EGFR mutations. CONCLUSIONS: Cytology specimens had a diagnostic performance for the detection of EGFR mutations that was comparable to that of tissues. For detecting EGFR mutations, pyrosequencing or PNA clamping was more sensitive than direct sequencing. In EGFR mutation negative patients who are difficult to obtain tissue, repeating test using pyrosequencing or PNA clamping is recommended to improve the detection rate of EGFR mutation than only one, especially in cytology.