Increased expression of α5β1-integrin is a prognostic marker for patients with gastric cancer

The study was to evaluate the association of expression level of alpha 5 beta 1-integrin with clinicopathologic features and prognosis in gastric cancer (GC). The expression of alpha 5 beta 1-integrin in normal gastric mucosa and GC tissue was detected with immunohistochemistry. The level of alpha 5 and beta 1 mRNA in GC tissues and non-neoplastic tissues was evaluated in 48 paired cases by quantitative real-time polymerase chain reaction (qRT-PCR). Survival analysis by the Kaplan-Meier method was performed to assess prognostic significance. The alpha 5 beta 1-integrin expression was detected in 68.3 % (127/186) GC samples, and there was a significant difference on their positive expression rate between GC tissue and normal gastric mucosa (P < 0.001). The positive expression rate of alpha 5 beta 1-integrin in patients with poor histologic differentiation (P = 0.001), lymph node metastasis (P < 0.001), and recurrence (P < 0.001) group was heightened. Using Kaplan-Meier analysis, a comparison of survival curves of low versus high expresser of alpha 5 beta 1-integrin revealed a highly significant difference in human GC tissue (P = 0.002), which suggested that overexpression of alpha 5 beta 1-integrin is associated with a worse prognosis. Multivariate analyses showed that alpha 5 beta 1-integrin expression was independent risk factor predicting overall survival [Hazard ratio (HR) 1.594, 95 % confidence interval (CI) 1.236-2.408, P = 0.006] and disease-free survival [HR 3.952, 95 % CI 1.676-9.861, P = 0.003] in GC. The alpha 5 beta 1-integrin promotes angiogenesis and associates with lymph node metastasis, vascular invasion and poor prognosis of GC. The current study shows that alpha 5 beta 1-integrin may be an independent prognostic factor for GC patients.