Epidermal Growth Factor Receptor (EGFR) Expression in Operable Non-small Cell Lung Carcinoma

This study was performed to assay the expression of epidermal growth factor receptor (EGFR) in non-small cell lung carcinoma (NSCLC), and to investigate the relationship between EGFR status and various clinicopathologic features of NSCLC, including angiogenesis and proliferative activity. The expression of EGFR, microvessel count (MVC) measured by CD31 monoclonal antibody, and proliferative activity using Ki-67 labeling index were immunohistochemically analyzed in formalin-fixed and paraffin-embedded tissue specimens from 65 patients with completely resected stage II-IIIA NSCLC. Pathologic and clinical records of all patients were retrospectively reviewed. EGFR was expressed in 18 (28%) of 65 NSCLC samples. More squamous tumors (35%) were EGFR-positive than other NSCLCs (23%) (p-value 0.308). There was a statistically significant correlation between EGFR expression and Ki-67 labeling index (p-value 0.042), but no correlation was observed between EGFR expression and tumor histology, stage, or MVC. There were no differences between EGFR positive and negative tumors in 5-yr disease-free survival (60% vs. 52%, p-value 0.5566) and 5-yr overall survival (53% vs. 45%, p-value 0.3382) rates. In conclusion, our findings suggest that NSCLC proliferative activity may be dependent on EGFR expression, but that EGFR expression had no significant impact on survival in curatively resected NSCLC.