Clinicopathological and prognostic significance of aberrant Arpin expression in gastric cancer

AIM: To detect the expression of Arpin, and determine its correlation with clinicopathological characteristics and the prognosis of gastric cancer (GC) patients. METHODS: A total of 176 GC patients were enrolled as study subjects and classified into groups according to different clinicopathological variables. GC mucosal tissues were obtained via surgery. Another 43 paraffin-embedded tissue blocks of normal gastric epithelium (> 5 cm away from the edge of the tumor) were included in the control group. Immunohistochemistry (IHC) for the Arpin and Arp3 proteins was performed on the formalin-fixed, paraffin-embedded GC tissues. Additionally, expression of the Arpin protein in 43 normal gastric tissues was also determined using IHC. RESULTS: Expression of the Arpin protein in GC was lower than that in normal gastric mucosa (30.68% vs 60.47%, P < 0.001). A χ(2) test of the 176 GC samples used for IHC showed that decreased Arpin expression was associated with advanced TNM stage (P < 0.01) and the presence or absence of lymph node metastasis (80.92% vs 35.56%, P < 0.001). Additionally, a significant correlation was observed between the expression of Arpin and the presence of the Arp2/3 complex in GC tissues (χ(2) = 30.535, P < 0.001). Moreover, a multivariate Cox regression analysis revealed that Arpin expression [hazard ratio (HR) = 0.551, P = 0.029] and TNM stage (HR = 5.344, P = 0.001) were independent prognostic markers for overall survival of GC patients. Regarding the 3-year disease-free survival (DFS), the recurrence rate of GC patients with low Arpin expression levels (median DFS 19 mo) was higher than that in the high-Arpin-expression group (median DFS 34 mo, P = 0.022). CONCLUSION: Low Arpin levels are associated with clinicopathological variables and a poor prognosis in GC patients. Arpin may be regarded as a potential prognostic indicator in GC.