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 (p<0.05): EGFR gene amplification was associated with a lower 5-year survival rate.
CONCLUSION
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.