Abstract
EGFR mutations correlate with improved clinical outcome whereas KRAS mutations are associated with lack of response to tyrosine kinase inhibitors in patients with non-small cell lung cancer (NSCLC). Endobronchial ultrasound (EBUS)-transbronchial needle aspiration (TBNA) is being increasingly used in the management of NSCLC. Co-amplification at lower denaturation temperature (COLD)–polymerase chain reaction (PCR) (COLD-PCR) is a sensitive assay for the detection of genetic mutations in solid tumours. This study assessed the feasibility of using COLD-PCR to screen for EGFR and KRAS mutations in cytology samples obtained by EBUS-TBNA in routine clinical practice. Samples obtained from NSCLC patients undergoing EBUS-TBNA were evaluated according to our standard clinical protocols. DNA extracted from these samples was subjected to COLD-PCR to amplify exons 18–21 of EGFR and exons two and three of KRAS followed by direct sequencing. Mutation analysis was performed in 131 of 132 (99.3%) NSCLC patients (70F/62M) with confirmed lymph node metastases (94/132 (71.2%) adenocarcinoma; 17/132 (12.8%) squamous cell; 2/132 (0.15%) large cell neuroendocrine; 1/132 (0.07%) large cell carcinoma; 18/132 (13.6%) NSCL-not otherwise specified (NOS)). Molecular analysis of all EGFR and KRAS target sequences was achieved in 126 of 132 (95.5%) and 130 of 132 (98.4%) of cases respectively. EGFR mutations were identified in 13 (10.5%) of fully evaluated cases (11 in adenocarcinoma and two in NSCLC-NOS) including two novel mutations. KRAS mutations were identified in 23 (17.5%) of fully analysed patient samples (18 adenocarcinoma and five NSCLC-NOS). We conclude that EBUS-TBNA of lymph nodes infiltrated by NSCLC can provide sufficient tumour material for EGFR and KRAS mutation analysis in most patients, and that COLD-PCR and sequencing is a robust screening assay for EGFR and KRAS mutation analysis in this clinical context.
Highlights
Epidermal growth factor receptor (EGFR) is a member of the ErbB receptor family, a key regulator of epithelial cell proliferation [1]
Endobronchial ultrasound (EBUS)-transbronchial needle aspiration (TBNA) 132 patients diagnosed with non-small cell lung cancer (NSCLC) using EBUS-TBNA
We report on the feasibility of using Co-amplification at lower denaturation temperature (COLD)-polymerase chain reaction (PCR) to screen for EGFR and Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations in 132 patients that had been sampled by EBUS-TBNA according to our standard clinical protocols
Summary
Epidermal growth factor receptor (EGFR) is a member of the ErbB receptor family, a key regulator of epithelial cell proliferation [1]. Excessive EGFR signaling upsets the balance between cell growth and apoptosis contributing to tumourigenesis in a wide variety of solid tumours including non-small cell lung cancer (NSCLC) [2]. This can arise from overexpression of EGFR, its signaling partners, or two of its ligands, EGF and TGFa [3,4]. Constitutive activation of EGFR tyrosine kinase activity can be brought about by somatic mutations in the tyrosine kinase domain of EGFR [5,6,7].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
