Cyclooxygenase-2 expression in chronic gastritis and gastric carcinoma, correlation with prognostic parameters

Cyclooxygenase-2 (Cox-2) is the inducible form of cyclooxygenase enzyme. Cox-2 is induced in numerous processes such as cellular growth, differentiation, inflammation and tumorogenesis.

Assessment of Cox-2 expression in chronic gastritis and gastric carcinoma.

Sixteen chronic gastritis (CG) and 43 gastric carcinoma cases were subjected to an immunohistochemical approach using anti Cox-2 antibody.

All CG cases displayed positive epithelial Cox-2 expression with only 25% positivity for stromal expression. Eighty six percent of gastric carcinoma showed epithelial Cox-2 expression that was significantly correlated with lymph node involvement (p<0.01), advanced stage (p=0.01), high microvessel density (MVD) (p=0.0001), vascular invasion (p=0.002), perineural invasion (p=0.01) and low apoptotic count (p<0.0001). Stromal Cox-2 expression was seen in 79% of gastric carcinoma cases and was significantly associated with low apoptotic count (p=0.0007), vascular invasion (p=0.001) and high microvessel density (MVD) (p=0.0003). Only stromal Cox-2 expression was significantly higher in gastric carcinoma than chronic gastritis (p=0.0001).

Cox-2 appears to be involved in gastric carcinoma progression as it promotes angiogenesis, suppresses apoptosis and facilitates invasion and metastasis. Double expression of Cox-2 in gastric carcinoma epithelium and stroma and significant association between them demonstrate a paracrine cross effect between stromal and malignant epithelium.