Objective Elevated serum levels of vascular endothelial growth factor(VEGF)and COX-2 are associated with poor prognosis in patients with gastric cancer.Little is known about the clinical benefit of combining Celecoxib,a selective inhibitor of cyclooxygenase 2(COX-2),with standard chemotherapy regimens for gastric cancer patients.In this study,we measured the effect of combinatorial use of Celecoxib with standard chemotherapy on the serum levels of VEGF and COX-2 in patients with gastric cancer.Methods 80 patients with gastric cancer underwent laparoscopic radical surgery were randomized to two groups: the combination group(Celecoxib plus standard chemotherapy FOLFOX4)(n=40),and FOLFOX4 alone group(n=40).In combination group,Celecoxib was given orally to the patients(400 mg,twice daily).Serum levels of VEGF and COX-2 were measured by ELISA before and after surgery.Results No significant difference in serum levels of VEGF and COX-2 was found between the combination group and FOLFOX4 alone group prior to chemotherapy(p>0.05).Following six cycles of chemotherapy,there was a greater decrease in the serum levels of VEGF and COX-2 in the combination group than in the FOLFOX4 group(p<0.01).In addition,the serum levels of VEGF and COX-2 were closely correlated in patients with gastric adenocarcinoma before treatment.Conclusion When combined with standard chemotherapy,Celecoxib could reduce the serum levels of VEGF and COX-2,implying that COX-2 inhibitor may have a therapeutic application through inhibition of tumor angiogenesis and prevention of recurrence or metastasis.Thus,Celecoxib may be a useful adjuvant agent to standard chemotherapy in patients with advanced gastric cancer.