Relationship between Expression of TGF-β1, Smad2, Smad4 and Prognosis 
of Patients with Resected Non-small Cell Lung Cancer

Abstract

Background and objective It has been proven that any changes of transforming growth factor β (TGF-β)-Smad signal transduction pathway will lead to abnormalities of signal transmission and the out of control during cell growth and differentiation, resulting in cancer development. The aim of this study is to investigate the prognostic values of TGF-β1, Smad2 and Smad4 in resected non-small cell lung cancer (NSCLC). Methods The expression of TGF-β1, Smad2, and Smad4 was evaluated by immunohistochemistry in 85 patients with NSCLC. The relationships among the expression of these proteins, clinicopathological factors, and prognosis were also analyzed. Results TGF-β1 positive expression was significantly correlated with the late stage and lymph node involvement. No significant association existed between the expression of Smad2 and the clinicopathological characteristics. The lack of Smad4 expression was associated with the advanced tumor stage (P=0.014). Multivariate analysis indicated that lymph node involvement (P=0.001) was an independent prognostic factor in the 85 NSCLC patients. The positive expression levels of TGF-β1 (P=0.032) and N stage (P=0.028) were demonstrated to be independent risk factors for survival among 47 lung adenocarcinoma patients. Adenocarcinoma patients with TGF-β1 positive expression demonstrated an unfavorable survival outcome (P=0.0376). Conclusion TGF-β1 may be an independent predictor of survival in resected lung adenocarcinoma patients.

Keywords

• Transforming growth factor β
• Smad
• Lung neoplasms