Decreased tumstatin-mRNA is associated with poor outcome in patients with NSCLC

Tumstatin is a candidate tumor suppressor that plays an important role in tumor growth and angiogenesis. The purpose of this study was to evaluate the correlation between tumstatin-mRNA expression and the clinicopathologic characteristics, tumor angiogenesis, outcome of patients with non-small cell lung cancer (NSCLC). Specimens from 68 patients with NSCLC were recruited in this study. Tumstatin-mRNA expression and protein level in tumor tissues were quantified respectively by quantitative RT-PCR and ELISA. Microvessel density (MVD) was determined by CD34 immunostaining. The correlation of tumstatin-mRNA expression levels with clinicopathologic variables, tumor angiogenesis, and prognosis was analyzed. Tumstatin-mRNA expression levels were decreased in tumor. Tumstatin-mRNA expression level was significantly correlated with its protein level in tumor (r = 0.562; P = 0.001). Tumstatin-mRNA expression levels in poorly differentiated tumor tissues were significantly lower than in well-differentiated tumor tissues (P < 0.004). Furthermore, tumor tumstatin-mRNA expression were also significantly related to tumor pathologic stage (P = 0.032) and MVD (r = -0.77, P < 0.0001). Overall survival (OS) and disease-free survival (DFS) analysis indicated that NSCLC patients with low tumstatin-mRNA expression had poorer OS and DFS than those with high expression (P = 0.015 and 0.037; respectively). Multivariable Cox regression analysis revealed that the tumstatin-mRNA expression could be an independent prognostic indicators in both DFS and OS. Tumstatin-mRNA expression levels are down-regulated in NSCLC tissues. Tumstatin-mRNA expression level correlates with prognosis, which suggests that tumstatin-mRNA is a new potential independent marker of favorable prognosis in NSCLC.