Abstract: To investigate the possible role of Helicobacter pylori ( Hp) infection in the development of gastric cancer. Method: Immunohistochemical staining was used to detect the expression of COX2 in 12 cases of chronic superficial gastritis, 30 cases of chronic atrophic gastritis (including 12 cases of intestinal metaplasia and 18 cases of dysplasia )and 20 cases of gastric cancer. Hp was assessed by using rapid urease staining test combined with HE staining test. Results: The infection of HP in gastric carcinoma was found in 12 cases(12/20,60%), and there was no significant difference in the positive rate of COX2 between dysplasia and gastric cancer or intestinal metaplasia(P＞ 0.05), and their expression level were intensive in Hp positive patients when compared with Hp negative patients in precancerous lesions(P＜0.05). Conclusion: C0X2 gene expression is accelerated in early gastric cancer. Hp might act as a tumor promoter in the genesis of gastric carcinoma.

Key words: Helicobacter pylori (Hp), Stomach neoplasms, Precancerous lesions, Cyclooxygenase