Triple Gene Analysis Using Samples Obtained by Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

Intern Med. 2016;55(21):3105-3111. doi: 10.2169/internalmedicine.55.6794. Epub 2016 Nov 1.

Abstract

Objective A mutational analysis of tumor tissue samples is an important part of advanced lung cancer treatment strategies. This study evaluated the efficacy of a triple gene analysis using samples obtained via endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Methods Either metastatic lymph nodes or primary lung mass samples obtained by EBUS-TBNA were collected between May 2011 and May 2013. We consecutively analyzed epidermal growth factor receptor (EGFR), V-Ki-ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS), and anaplastic lymphoma kinase (ALK) fusion genes using remnant tissue samples. Results A total of 109 patients were diagnosed with non-small cell lung cancer (NSCLC). Of these, 70% were adenocarcinoma, 27% squamous cell carcinoma with NSCLC, and 3% were related to other types of lung cancer. EGFR mutations were detected in 23 cases (21.1%), KRAS mutations in 13 cases (11.9%), and ALK fusion genes in 5 cases (4.9%). The ALK fusion genes could not be analyzed in four cases because of insufficient tissue samples remaining after routine histochemistry and an EGFR/KRAS mutation analysis. We found that small biopsy samples from EBUS-TBNA were adequate for performing a triple gene analysis in 97 patients (96%). ALK fusion protein immunohistochemistry (IHC) was 100% consistent with fluorescence in situ hybridization (FISH). Conclusion Small samples obtained by EBUS-TBNA were found to be sufficient for performing a triple gene analysis following routine histology and IHC. ALK IHC showed a very good concordance with FISH for detecting ALK fusion genes.

MeSH terms

  • Adenocarcinoma / genetics
  • Adenocarcinoma / pathology
  • Adult
  • Aged
  • Biopsy, Fine-Needle*
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / pathology
  • DNA Mutational Analysis*
  • ErbB Receptors / metabolism
  • Female
  • Genetic Testing*
  • Humans
  • Immunohistochemistry
  • In Situ Hybridization, Fluorescence
  • Lung / pathology*
  • Lung Neoplasms / genetics*
  • Lung Neoplasms / pathology*
  • Lymph Nodes / pathology*
  • Lymphatic Metastasis / genetics
  • Lymphatic Metastasis / pathology
  • Male
  • Middle Aged
  • Mutation
  • Proto-Oncogene Proteins p21(ras) / metabolism
  • Ultrasonography, Interventional*

Substances

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