Expression of cyclooxygenase-2 in human gastric adenomas and adenocarcinomas

Background and Objectives: The increased expression of cyclooxygenase (COX) -2 has been implicated in the development and progression of colorectal can cer. We sought to determine the involvement of COX-2 in human gastric cance r. Materials and Methods: COX-2 mRNA was assayed in both gastric cancer cell l ines and biopsy specimens from 37 gastric adenocarcinomas, five gastric ade nomas, and five hyperplastic polyps by reverse transcription-polymerase cha in reaction. Results: COX-2 mRNA was found in four of five gastric cancer cell lines, tw o from intestinal type and two from diffuse type. COX-2 mRNA was expressed in 19 of 37 (51%) human gastric cancer specimens. The tumor diameter was gr eater in patients with COX-2 expression than in those without (6.5 +/- 4.6 vs. 3.8 +/- 2.7 cm, P < 0.05). The incidence of COX-2 mRNA expression was s ignificantly higher in patients with pT2-pT4 tumors than in those with pT1 tumors (71 vs. 35%, P < 0.05). Significantly higher expression of COX-2 mRN A was also observed in patients with lymph node involvement than in those w ithout (75 vs. 40%, P < 0.05). COX-2 mRNA was found in one of five adenomas , while it was absent in five hyperplastic polyps. The paired normal gastri c musosa did not express COX-2 mRNA in any of the 47 patients. Conclusions: These results provide clinical evidence that COX-2 may contrib ute to tumor progression in human gastric adenocarcinoma. J. Surg. Oncol. 2 001,76:26-30 (C) 2001 Wiley-Liss, Inc.