B7-H3 and B7-H4 are independent predictors of a poor prognosis in patients with pancreatic cancer

B7-H3 and B7-H4 belong to the peripheral membrane protein B7 family and are hypothesized to regulate immunity. These proteins are expressed in human pancreatic cancer (PC), but their prognostic significance is poorly understood. The present study examined the association between B7-H3 and B7-H4 expression and the overall survival time in patients with PC that underwent surgery at the Second Affiliated Hospital to Zhengzhou University between April 2000 and January 2009. Immunohistochemical analysis demonstrated that B7-H3 and B7-H4 were expressed in 35 (88%) and 30 (75%) tumor tissue samples, respectively, which were obtained from 40 patients with PC. Statistical analysis revealed that B7-H3 expression was associated with an early tumor-node-metastasis stage (stage I and II; P<0.01), and B7-H4 expression was associated with tumors located in the body and tail of the pancreas (P<0.01) and lymph node metastasis (P=0.02). In addition, using Spearman's rank correlation coefficient, the present study demonstrated a positive correlation between B7-H3 expression and B7-H4 expression (r=0.37; P=0.02) in tumor samples. B7-H4 expression (P=0.01), tumors located in the pancreatic body and tail (P<0.01), lymph node metastasis (P=0.02) and combined B7-H3 and B7-H4 expression (P<0.01) were indicators of a poor overall survival time. However, solitary B7-H4 expression (P=0.03) and combined B7-H3 and B7-H4 expression (P=0.04) remained significant prognostic factors following adjustment for other prognostic factors in a multivariate Cox's proportional hazards regression model. Therefore, the present results indicate that solitary B7-H4 expression and a combination of B7-H3 and B7-H4 expression are independent predictors of a poor prognosis in patients with PC.