Expression of midkine and vascular endothelial growth factor in gastric cancer and the association of high levels with poor prognosis and survival

The aim of the present study was to investigate the expression of midkine (MK) and vascular endothelial growth factor (VEGF) in gastric cancer and its relationship with gastric cancer prognosis and survival rate. We recruited 107 patients with complete clinical data and available tissue samples [gastric cancer tissue (n=107); adjacent normal gastric mucosa (n=31)]. MK and VEGF expression in these tissues were assayed by immunohistochemistry. The association of MK or VEGF expression with various prognostic factors in gastric cancer and the 5-year survival of gastric cancer patients were analyzed. MK and VEGF immunoreactivity were detected in 69.2% (74 out of 107 cases) and 66.4% (71 out of 107 cases) of gastric cancer tissues, but not in normal gastric tissues (P=0.00). MK and VEGF expression was correlated with tumor size, depth of invasion, lymph node metastasis and pathological stage (P<0.01), but not with age and gender (P>0.05). MK expression was positively correlated with VEGF expression (r=0.681, P<0.01). In addition, MK or VEGF expression was negatively correlated with the 5-year survival rate (P<0.01). The 5-year survival rate was significantly higher in patients with MK- or VEGF-immunonegative tumors than in patients with immunopositive ones (P<0.01). Co-expression of MK and VEGF was an independent predictor of gastric cancer prognosis. Expression of MK and VEGF is increased in gastric cancer and increased expression is closely correlated with poor prognosis and survival.