Clinicopathologic association of cyclooxygenase 1 and cyclooxygenase 2 expression in gastric adenocarcinoma

Objective To evaluate the association of clinicopathologic factors and prog nostic value with the expression of cyclooxygenase 1 and 2 in patients with gastric adenocarcinoma. Summary Background Data Epidemiologic studies have indicated that nonsteroi dal antiinflammatory drugs reduce the risk of colon cancer by as much as 40 % and also decrease the risk of gastric cancer. Recently, gastric cancer wa s found to express constitutive cyclooxygenase 1 and inducible cyclooxygena se 2 isoenzymes. Nonsteroidal antiinflammatories, which may function as cyc looxygenase inhibitors, inhibited the growth of gastric cancer cells. These two isoenzymes' expressions associated with traditional clinicopathologic factors have not been fully evaluated, and their prognostic value for deter mining survival in patients remains to be clarified. Methods Seventy-one specimens resected from patients with gastric adenocarc inoma were investigated by immunohistochemical stain against cyclooxygenase 1 and 2. The 71 specimens were divided into stain-positive and stain-negat ive groups. Correlations between cyclooxygenase 1 and 2 expression, various clinicopathologic factors *including vascular invasion and Helicobacter py lori infection), and prognosis were studied. Results The cyclooxygenase 2-positive group was significantly correlated wi th vascular invasion and H. pylori infection by univariate and multivariate analysis. In patients with cyclooxygenase 2-positive cancer, the prognosis was significantly poorer than in those with cyclooxygenase 2-negative canc er. However, multivariate analysis showed that vascular invasion, serosal i nvasion, and lymph node metastasis were independent prognostic factors for patients with gastric cancer, but cyclooxygenase 2 expression was not. Ther e was no significant correlation between cyclooxygenase 1 expression and cl inicopathologic factors and prognosis. Conclusions Upregulated cyclooxygenase 2 expression was associated with H. pylori infection in gastric cancer and was also strongly correlated with po sitive vascular invasion, which was an independent prognostic factor for po orer survival in this study. The usefulness of cyclooxygenase 2 inhibitors in the prevention or treatment of gastric cancer remains undetermined but d eserves further investigation.