Background : Abnormal over-expression or gene amplification of epidermal growth factor
receptor (EGFR) is important in the prognosis of non-small cell lung cancer (NSCLC). We
investigated the frequency of EGFR protein expression and gene amplification, and the correlation
between EGFR status and survival in NSCLC. Methods : We examined 360 cases
of microarrayed NSCLC tissues for the EGFR protein expression and EGFR gene amplification
using immunohistochemistry and fluorescent in situ hybridization. Results : EGFR protein
expression and EGFR gene amplification occurred in 110 cases (30.6%) and 24 cases
(6.7%), respectively. EGFR protein expression and gene amplification were more frequent in
squamous cell carcinoma than in adenocarcinoma. Differences in EGFR protein expression
did not dramatically affect survival curves (p=0.740), but differences in gene amplification did
: EGFR protein expression and gene amplification showed moderate correlation with
each other. EGFR gene amplification predicted a poor prognosis, whereas EGFR protein
expression did not.