INTRODUCTION:

Epidermal growth factor receptor (EGFR) mutations are a strong determinant factor of response to EGFR tyrosine kinase inhibitors in non-small cell lung cancer (NSCLC). Now some methods have been used to detect EGFR mutations and they have approximately the same sensitivity and specificity. In a case, we experienced unmatched results from two methods of detecting EGFR mutations. In this study, we compared data from three methods of detecting mutations.

METHODS:

We obtained 30 samples of operation, transbronchial lung biopsy, bronchoscopic brushing, pleural effusion and lymph nodes from NSCLC patients. EGFR mutation status was determined by two or three methods (mutant-enriched PCR method, PNA-LNA PCR Clamp method and PCR invader method).

RESULTS:

method (n=31)mutation positive
2 method (n=20) m.e./Clamp (n=10) 4/4 
  m.e./invader (n=2) 1/0 
  Clamp/invader (n=8) 4/3 
3 method (n=10) m.e./Clamp/invader (n=10) 3/2/3 
method (n=31)mutation positive
2 method (n=20) m.e./Clamp (n=10) 4/4 
  m.e./invader (n=2) 1/0 
  Clamp/invader (n=8) 4/3 
3 method (n=10) m.e./Clamp/invader (n=10) 3/2/3 
m.e.: mutant-enriched PCR, Clamp: PNA-LNA PCR Clamp, invader: PCR invader

EGFR mutations were detected in 12 samples. Mutation statuses of two or three methods were matched in 9 samples, but 3 samples were unmatched.

CONCLUSIONS:

EGFR mutation statuses were unmatched in same samples. EGFR gene status is essential information for NSCLC patients. We need to take false negative into consideration in the clinical setting and need father deliberation about detecting methods of EGFR mutations.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2110.