ABSTRACT
<p><b>OBJECTIVE</b>To investigate COX-2 expression in patients with gastric cancer and its relationship with angiogenesis and clinicopathologic features of gastric cancer.</p><p><b>METHODS</b>COX-2 expression and CD34-stained microvessel density (MVD) were detected by immunohistochemical methods in specimens from 96 patients with gastric cancer. The correlations among COX-2 expression, MVD and clinicopathologic features were analyzed.</p><p><b>RESULTS</b>The COX-2 positive rate and MVD in gastric cancer were significantly higher than those in the normal gastric mucosa (80.2% vs. 13.3%; 32.5+/- 8.3 vs. 13.1+/- 2.4, all P< 0.01). The COX-2 positive rate and MVD in the patients with stage III and IV were significantly higher (91.4% and 34.9+/- 8.7 respectively, P< 0.01), than that in the patients with stage I and II. The COX-2 positive rate and MVD in the cases with lymph node metastasis were 87.9% and (35.0+/- 8.5) respectively, higher than those in the cases without lymph node metastasis (P< 0.05). The Spearman rank correlation test showed a significant correlation between COX-2 expression and tumor MVD (r=0.311, P< 0.01).</p><p><b>CONCLUSIONS</b>COX-2 plays an important role in gastric cancer angiogenesis. COX-2 and angiogenesis induced by COX-2 contribute to tumor invasion and lymph node metastasis.</p>