Screening for EGFR and KRAS mutations in endobronchial ultrasound derived transbronchial needle aspirates in non-small cell lung cancer using COLD-PCR

PLoS One. 2011;6(9):e25191. doi: 10.1371/journal.pone.0025191. Epub 2011 Sep 19.

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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenocarcinoma / diagnosis
  • Adenocarcinoma / genetics
  • Aged
  • Aged, 80 and over
  • Biopsy, Fine-Needle
  • Bronchi / diagnostic imaging*
  • Carcinoma, Large Cell / diagnosis
  • Carcinoma, Large Cell / genetics
  • Carcinoma, Non-Small-Cell Lung / diagnosis*
  • Carcinoma, Non-Small-Cell Lung / genetics*
  • Carcinoma, Squamous Cell / diagnosis
  • Carcinoma, Squamous Cell / genetics
  • DNA, Neoplasm / genetics
  • Endosonography
  • ErbB Receptors / genetics*
  • Feasibility Studies
  • Female
  • Humans
  • Lung Neoplasms / diagnosis
  • Lung Neoplasms / genetics
  • Lymphatic Metastasis
  • Male
  • Middle Aged
  • Mutation / genetics*
  • Polymerase Chain Reaction / statistics & numerical data*
  • Prognosis
  • Proto-Oncogene Proteins / genetics*
  • Proto-Oncogene Proteins p21(ras)
  • ras Proteins / genetics*

Substances

  • DNA, Neoplasm
  • KRAS protein, human
  • Proto-Oncogene Proteins
  • EGFR protein, human
  • ErbB Receptors
  • Proto-Oncogene Proteins p21(ras)
  • ras Proteins