Epidermal growth factor receptor expression and gene copy number analysis in gastric carcinoma samples from Chinese patients

Epidermal growth factor receptor (EGFR) expression and gene copy number have been observed to be associated with a positive clinical response to EGFR inhibitors. The present study aimed to evaluate EGFR expression and gene copy number in samples of gastric carcinoma (GC) from Chinese patients. EGFR expression and gene copy number were detected using immunohistochemistry and fluorescence in situ hybridization, in tissue array slides containing 150 individual samples of GC tissue. The association between EGFR status, clinicopathological features and overall patient survival was analyzed. Out of the 150 cases of GC evaluated, 63 (42.00%) demonstrated weak EGFR expression and 20 (13.33%) demonstrated EGFR overexpression. EGFR expression was observed to be associated with tumor location (P<0.05). Out of 104 cases of GC, which produced a clear FISH signal, 6 (5.77%) exhibited EGFR gene amplification and 5 (4.80%) exhibited balanced polysomy. Patients exhibiting GC, who demonstrated weak EGFR expression, EGFR overexpression or increased EGFR gene copy number, possessed an unfavorable prognosis. Multivariate analysis revealed that EGFR expression, tumor/node/metastasis stage and tumor location were potential independent unfavorable prognostic factors for GC patients. In conclusion, EGFR overexpression, gene amplification and polysomy were observed in GC patients and were associated with an unfavorable prognosis. Evaluation of EGFR status may therefore facilitate the identification of a subset of GC patients sensitive to treatment with EGFR-targeted therapies.