Expression of cyclooxygenase-2 in primary and remnant gastric carcinoma: comparing it with p53 accumulation, Helicobacter pylori infection, and vascular endothelial growth factor expression.

BACKGROUND AND OBJECTIVES: Cyclooxygenase-2 (COX-2) expression may contribute to the synthesis of prostanoids, which have been related to carcinogenesis and tumor progression. It is well known that the gastric remnant is at greater risk of the development of gastric cancer than is the whole stomach; incidence rates for gastric cardia adenocarcinoma are rising in the United States and Europe. Our objective was to determine the involvement of COX-2 in primary and remnant gastric cancer tissues as well as in adjacent noncancerous mucosa.

METHODS: We investigated the expression of COX-2 in 91 human gastric cancer tissue and adjacent noncancerous mucosa samples (40 remnant gastric cancer, 37 gastric cardia cancer, and 14 gastric corpus and antrum cancer), using immunohistochemistry. In addition, p53 expression, Helicobacter pylori infection, and vascular endothelial growth factor in the tissues were evaluated by immunohistochemical staining and compared with COX-2 expression.

RESULTS: There were no significant differences in clinicopathological data in the gastric cancer tissues. There was a significant relation between the expression of COX-2 and p53 in gastric cancer tissues (P = 0.0048). However, vascular endothelial growth factor expression and Helicobacter pylori infection showed no correlation with the expression of COX-2. In the case of adjacent noncancerous mucosa, the positive rate of COX-2 expression was significantly higher in the remnant gastric cancers (75.0%) than in the primary gastric cancers (25.5%) (P < 0.0001).

CONCLUSIONS: This information may help in the analysis of the carcinogenesis of gastric cancer; there is also a possibility that the COX-2 selective inhibitor to the remnant gastric cancer has a chemopreventive effect.