EGFR and COX-2 protein expression in non-small cell lung cancer and the correlation with clinical features

To evaluate the expression of EGFR and COX-2 and their correlation with prognosis in NSCLC METHODS: The paraffin embedded tumor samples of 50 NSCLC patients receiving radical resection were analyzed immunohistochemically for EGFR and COX-2 expression and their prognostic values were explored.

The positive rate of EGFR protein in NSCLC tumor cells was 46%, which was significantly higher than its expression in normal lung (p = 0.0234) and paracancerous tissues (p = 0.020). EGFR expression was significantly higher in nodal positive than in nodal negative patients (p = 0.04). The mean survival time for EGFR positive patients (31 months) was significantly lower than that for patients with EGFR negative expression (48 months) (p = 0.008,). In patients receiving post-operation thoracic irradiation, the mean survival time for EGFR positive patients was significantly lower than that for patients without EGFR positive expression (25 vs. 48 months, P = 0.004). The positive rate of COX-2 protein expression in NSCLC tumor cells was 90%, which was significantly higher than that in normal tissue(p = 0.00) and paracancerous tissue (p = 0.00). There was no correlation between COX-2 expression and patient survival, and no correlation between COX-2 and EGFR protein expression (P = 0.555).

COX-2 and EGFR are over-expressed in NSCLC. EGFR is an independent prognostic factor and a predictive factor for radiotherapy response in NSCLC.