Epidermal growth factor receptor overexpression correlates with a poor prognosis in completely resected non-small-cell lung cancer

Background: We designed a prospective study to test epidermal growth factor receptor (EGFR) expression by immunohistochemistry (IHC) in resected stage I-IIIA non-small-cell lung cancer (NSCLC) and to correlate overexpression with survival. Patients and methods: EGFR expression was evaluated in 130 consecutive NSCLC patients after radical surgery (60 squamous cell carcinomas, 48 adenocarcinomas, 22 large cell carcinomas: stage I, 41 (31%); stage II, 37 (29%) and stage IIIA, 52 (40%). Results: Overall, 101 of 130 (78%) specimens expressed EGFR, and with a cut-off value of 10% positive cells 48 cases (37%) were classified as positive. At univariate analysis, EGFR was significantly more expressed in stage III (50%) than stage I (20%) and stage II (25%) (P<0.03). No correlation with histotype was found. After a median follow-up of 84 months, both median survival time (18 versus 50 months), 2-year (43% versus 70%) and 5-year (31% versus 46%) survival rates of positive cases were significantly lower than negative ones [P<0.001; hazard ratio 1.96; 95% confidence interval (CI) 1.16-3.30]. At the multivariate analysis, EGFR overexpression and stage emerged as independent factors for cancer-related mortality. Conclusion: in patients with radically resected stage I-IIIA NSCLC, EGFR overexpression predicts shorter survival, thus representing a valuable prognostic factor.