Expression of Epidermal Growth Factor Receptor and the association with Demographic and Prognostic Factors in Patients with Non-small Cell Lung Cancer

Introduction: Growth, proliferation, survival, and differentiation are the prominent characteristics of cells, which are affected by cancer. Epidermal growth factor receptor (EGFR) plays a pivotal role in the effective control of these features. Given the significance of EGFR signaling pathway in non-small cell lung cancer (NSCLC), EGFR expression is influential on these cell characteristics. In this paper, we studied EGFR expression and its association with demographic factors, clinicopathological features, and prognosis of NSCLC patients. Materials and Methods: In this retrospective cohort study which was done during 2009-12 at Ghaem Hospital, Mashhad, Iran. EGFR expression was evaluated in 96 patients with formalin-fixed, paraffin-embedded NSCLC tissues (43 adenocarcinomas, 48 squamous-cell carcinomas, and 5 large-cell carcinomas) using immunohistochemistry (IHC). Data analysis was performed by SPSS version 20.0. Results: Out of 96 specimens, approximately 53% were classified as positive for EGFR expression. The study group consisted of 68% (N=65) male and 32% (N=31) female subjects, with the mean age of 61.1±9.03 years. There was no difference between EGFR-positive and EGFR-negative patients in terms of the overall survival rate (P=0.49). In addition, no association was observed between tumor histology and EGFR expression (P=0.08), while EGFR-positive adenocarcinoma (N=28, 29%) was more prevalent compared to other subtypes of NSCLC. Moreover, there were no differences between tumor subtypes and the overall survival rate of the patients (P=0.21), and no association was found between EGFR expression and the patients’ demographic factors (e.g. age and gender). Conclusion: The results of this study indicated that EGFR expression could not be a prognostic marker in NSCLC patients; however, it seems that using standardized IHC scoring is likely to yield more reliable data in this regard.