EGR-1Protein Expression In Lung Squamous Cell Carcinoma Tissues And Its Clinical Significance

Objectives:To detect the expression levels of early growth response gene-1(EGR-1) protein in human lung squamous cell carcinoma tissues, and to investigate the relationship of EGR-1protein expression with clinicopathologic factors and prognosis.Methods:Carcinoma and corresponding paracancerous tissues were obtained from83lung squamous cell carcinoma patients (who had been treated in Qilu Hospital of Shandong University during Jan.2007to Dec.2007) with pulmonary resection and systematic lymphadenectomy. Immunohistochemical staining (SP method) was performed to detect the expression level of EGR-1in the carcinoma tissues and corresponding paracancerous tissues. All statistical analyses were performed with SPSS18.0statistical software. The χ2test was used to analyze the relationship between EGR-1protein expression and patients’ clinicopathologic factors, Kaplan-Meier method was used to calculate the5-year survival rate of patients, Log-rank test was used to compare survival differences, and Cox regression analysis was used to determine the independent prognostic factor.Results:The expression of EGR-1protein in lung squamous cell carcinoma tissues was significantly lower than that in paracancerous tissues(4.12±0.35vs6.90±4.58, P＜0.01). EGR-1protein low expression was not significantly associated with patient’s age(P=0.912)and gender(P=0.429),and the differentiation stage of tumor(P=0.289), but significantly associated with patient’s smoking history (P=0.025), tumor size (P=0.013), lymph node metastasis (P=0.003) and TNM stage of tumor (P=0.028). The patients with a low expression of EGR-1protein had a significantly low overall survival (2.5%vs15.9%, P=0.04) at5years after operation compared with patients with a high expression of EGR-1protein. TNM stage (P=0.020) and low expression of EGR-1protein (P=0.035) were independent prognosticators of patients with lung squamous cell carcinoma.Conclusion:EGR-1protein is low expressed in lung squamous cell carcinoma tissues, and its low expression in carcinoma cells was significantly associated with tumor progression and poor prognosis. Suggest that EGR-1protein may have clinical potential as a promising prognostic predictor and a possible therapeutic target for patients with lung squamous cell carcinoma.