Relation of cyclooxygenase-2 expression with premalignant gastric lesions

Introduction: We studied the relation between premalignant gastric lesions and cyclooxygenase-2 (COX-2) expression.

Methods: The study included 254 patients, who were histo- logically diagnosed with chronic active gastritis, atrophy, dys- plasia and metaplasia. Gastric biopsy specimens of the patients were histopathologically examined in terms of the presence of Helicobacter pylori (H. pylori) infection, atrophy The Operative Link for Gastritis Assessment ; (OLGA staging system), dysplasia (Vienna classification), and metaplasia (Sydney classification). COX-2 expression was investigated by immunohistochemical staining. COX-2 immunoreactivity score was calculated as the product of staining intensity and staining area. A score of >1 was defined as COX-2-positive expression.

Results: Of these patients, 84 (33.1%) had negative COX-2 expression (Score 0 and Score 1) and 170 (66.9%) had positive COX2 expression (Score 2 and Score 3). We found that in patients with a moderate-marked metaplasia, or with moderate-severe atrophy, a higher OLGA stage, or with dysplasia, the COX-2 expression was found to be higher than those with mild lesions. In 59.8% of the patients H. pylori was positive. While, the rate of severe atrophy was higher in H. pylori-positive patients ; no significant difference was determined between the H. pylori-positive and H. pylori-negative patients regarding age, smoking status, intestinal metaplasia grade, dysplasia, and COX-2 expression.

Conclusion: We found a relation between the level of COX-2 expression and the grade of premalignant gastric lesions. COX-2 plays an important role in the gradual process resulting eventually in gastric cancer.

Keywords: cyclooxygenase-2, atrophy, metaplasia, dysplasia.