Abstract: Objective   To investigate expression of Rac1 and NF-κB p65 in Non-Small Cell Lung Cancer(NSCLC) and their clinical significance.Methods   Immunohistochemical staning was applied to detect expression of Rac1 and NF-κB p65 in NSCLC group and control group.Correlations of expression of Rac1 and NF-?B p65 to clinical pathological parameters and prognosis and their correlations were analysed.Result    The expression intensities of Rac1 and NF-κB p65 in NSCLC were distinctly higher than those in control group.A correlation between the expression of Rac1 and NF-κB p65(r=0.656,P<0.001) was also associated with malignancy of NSCLC such as poor differentiation,high TNM stage and lymph node metastasis(P<0.05 or P<0.01). The 3-year survival rates were lower in patients with Rac1 high expression(35.29%) than those with low expression(79.07%) while the 3-year survival rates were lower in patients with NF-κB p65 high expression(40.28%) than those with low expression (74.36%).Further multivariate analysis suggested that both high expression of Rac1 and NF-κB p65 and lymph node metastasis were independent prognostic indicators for NSCLC(P<0.05,P<0.001).Conclusion     The expression of Rac1 in correlates with the expression of NF-κB p65 in NSCLC, which contributes the malignancy-related of NSCLC. Detecting the expression of Rac1 combined with NF-κB p65 in NSCLC tissue may give a clue on prongnosis of patient.

Key words: NF-kappa B, Carcinoma, Non-Small-Cell Lung, immunohistochemistry, prognosis, Kaplan-Meiers estimate, ras-related C3 botulinum toxin substrate 1