Detection of Epidermal Growth Factor Receptor (EGFR) Gene Mutation in Formalin Fixed Paraffin Embedded Tissue by Polymerase Chain Reaction-Single Strand Conformational Polymorphism (PCR-SSCP) in Non-Small Cell Lung Cancer in the Northeastern Region of Thailand

Abstract

Background: The use of targeted specific genes in therapeutic and treatment decisions has been considered for<br />lung cancer. The epidermal growth factor receptor (EGFR) gene, which is over expressed in non-small cell lung cancer<br />(NSCLC), was considered as one of the targeted specific genes. EGFR mutations in exons 18–21, which encode a<br />portion of the EGFR kinase domain, were found in NSCLC patients and were associated with the response of EGFRtyrosine<br />kinase inhibitors (EGFR-TKIs). Therefore, a molecular technique for EGFR mutation detection has important<br />benefits for therapy in NSCLC patients. This study aims to determine the EGFR mutations in patients with NSCLC<br />using polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) in exons 18-21. Methods:<br />DNA samples were extracted from formalin fixed paraffin embedded tissues of NSCLC patients who attended hospital.<br />The extracted DNA was used as a template for the EGFR gene amplification. Results: Occurrence of EGFR mutations<br />were found in 29 out of 50 cases (58%).The frequency of EGFR mutations by first PCR at exon 18, 19, 20 and 21<br />were 6 (12%), 19 (38%) 20 (40%) and at 21 (42%), respectively. By PCR-SSCP, the frequencies of EGFR mutations<br />at exon 18, 19, 20 and 21 were 3(6%), 18(36%), 23(46%) and 13(26%), respectively. All of the mutations found were<br />in agreement with DNA sequencings. Conclusion: The high frequency of EGFR mutations in NSCLC suggests that<br />PCR-SSCP is a efficient screening method and useful for treatment plan.