Clinical significance of EGFR expression in tumor stroma of NSCLC

Purpose: The clinical significance and biological functions of EGFR in tumor stroma of NSCLC were investigated. Methods: Immunohistological staining of EGFR was evaluated in 145 patients with NSCLC using two different antibodies (sc-03 from Santa Cruz Biotechnology and ab2430 from abcom). The correlations of EGFR expression in tumor stroma with clinicopathological features were detected. Kaplan-Meier analysis and Cox proportional hazard modeling were used to assess overall survival to analyze the effect of EGFR expression in tumor stroma on the prognosis of NSCLC. Results: The results of EGFR antibody sc-03 showed that EGFR expression in tumor stroma correlated significantly with clinical stage (X-2 = 7.51, P = 0.023), tumor size (X-2 = 6.28, P = 0.043) and examed axillary node metastases (X-2 = 3.94, P = 0.047). Patients with high EGFR expression level in tumor stroma showed poor survival (P = 0.001). Multivariate analysis showed that EGFR high expression in tumor stroma was an independent predictor for NSCLC patients (hazard ratio = 2.02; 95% confidence interval 1.16-3.50, P = 0.01). Another antibody ab2430 got the similar results, and EGFR expression in tumor stroma correlated significantly with clinical stage (X-2 = 14.95, P = 0.001) and tumor size (X-2 = 6.31, P = 0.043) and poor survival (P < 0.001). Furthermore, overexpressing EGFR in fibroblasts promoted the growth ability and colony formation ability of adjacent lung cancer cell. Conclusions: High levels of EGFR expression in tumor stroma were associated with aggressive clinical behaviors in NSCLC. Higher expression of EGFR in tumor stroma was an independent prognosis factor for NSCLC patients.