Clinical significance of E2F1 protein expression in non-small cell lung cancer

56 paired adjacent non-tumor/tumor matched samples were prospectively obtained from patients undergoing surgery for stage I-III NSCLC at Taipei Veterans General Hospital. The protein expression of E2F1 was determined by Western blot analysis. The levels of E2F1 protein were significantly higher in tumor samples than in non-tumor lung specimens (P？=？0.008). Overexpression of E2F1 was defined as a more than 2-fold expression in the tumorous sample compared with the corresponding nontumorous one, and was noted in 21 patients (37.5%). There was no significant difference in overall survival (P？=？0.44) or probability of freedom from recurrence (P？=？0.378) between patients with E2F1 overexpression vs. non-overexpressors. Additionally, there was no significant association between E2F1 overexpression and any clinicopathologic parameter such as histological type, stage, or angiolymphatic invasion of tumor.E2F1 protein is frequently overexpressed in NSCLC. There is no correlation between E2F1 protein expression and clinical outcome such as survival and freedom from progression.Lung cancer is the leading cause of cancer-related death globally, and non-small cell lung cancer (NSCLC) accounts for more than 80% of all lung cancers. Despite of advances in biomedical science, surgery remains the mainstay of treatment for early-stage NSCLC, and the result of surgical treatment alone is unsatisfactory. Therefore, there is an urgent need to identify biomarkers for prognostication of patients’ outcome after surgery. Prognostic markers can be used to select patients with increased risk of recurrence who may require more frequent surveillance and derive more benefit from adjuvant treatment. Many prognostic markers have been investigated in NSCLC such as mutation status of KRAS and p53, and expression of excision repair cross-complementation group 1 and ribonucleotide reductase subunit M1 [1-3].E2F1 belongs to the E2F family of transcription factors, and plays an important role in cell cyc