Comparison of epidermal growth factor receptor mutation analysis results between surgically resected primary lung cancer and metastatic lymph nodes obtained by endobronchial ultrasound‐guided transbronchial needle aspiration

Thoracic Cancer

Hironobu Okada¹  Takashi Anayama¹  Motohiko Kume¹  Kentaro Hirohashi¹  Ryouhei Miyazaki¹  Manabu Matsumoto² 

[1] Department of Surgery II, Kochi Medical School, Kochi Universtiy, Nankoku, Kochi, Japan;Laboratory of Diagnostic Pathology, Kochi Medical School Hospital, Nankoku, Kochi, Japan

关键词: EBUS‐TBNA;    EGFR mutation;    lung cancer;   

DOI  :  10.1111/j.1759-7714.2012.00122.x

来源: Wiley

【 摘 要 】

Abstract

Background:  Lung cancers with mutations in the epidermal growth factor receptor (EGFR) gene respond well to treatment with EGFR inhibitors. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is considered a useful modality to obtain samples from the mediastinal and hilar lymph nodes. However, the EGFR gene status of EBUS-TBNA samples may not always match that of primary tumors.

Methods:  In 14 node-positive patients diagnosed by EBUS-TBNA, EGFR mutation analysis results were compared between EBUS-TBNA samples and surgically removed primary tumors. EGFR mutation was screened with peptide nucleic acid-locked nucleic acid polymerase chain reaction (PNA-LNA PCR) clamp followed by direct sequence analysis. For one controversial case, gene mutation analyses were performed for the multiple micro-fractions of a metastatic lymph node, which exhibited the heterogeneous immunohistochemical features.

Results:  EBUS-TBNA diagnosed one case of exon 21 point mutations, one case of exon 19 deletion, and 12 cases of wild-type EGFR. Results were consistent with those of surgically removed primary tumors in 13 of 14 cases. One case of wild-type EGFR diagnosed by EBUS-TBNA exhibited exon 21 point mutation in the surgically removed primary tumor. The metastatic lymph node targeted by EBUS-TBNA mostly consisted of cancer cells with wild-type EGFR; however, a minor component positive for thyroid transcription factor-1 (TTF-1) and surfactant-associated protein A (PE-10) exhibited EGFR mutation.

Conclusion:  The combination of EBUS-TBNA and PNA-LNA clamp is useful for EGFR mutation analysis. However, EGFR mutation status in EBUS-TBNA samples may not be consistent with that of the primary tumor when the tumor contains few EGFR mutations.

【 授权许可】

Unknown   
© 2012 Tianjin Lung Cancer Institute and Blackwell Publishing Asia Pty. Ltd