COX-2 expression in gastric cancer and its relationship with angiogenesis using tissue microarray.

AIM

To explore the expression and clinicopathological significance of cyclooxygenase-2 (COX-2) and microvessel density (MVD) in gastric carcinogenesis, and to investigate their roles in the invasion and the relationship between biological behaviors and prognosis of gastric cancer.

METHODS

Using Envision immunohistochemistry, COX-2 and CD34 expressions in gastric cancer tissue array were examined. MVD was counted and the relationship between the biological behaviors and prognosis was analyzed.

RESULTS

The expression of COX-2 in gastric cancer tissue was significantly higher than that in normal mucosa (c2 = 12.191, P < 0.05). The over-expression of COX-2 in gastric cancer was obviously related to metastasis and depth of invasion (c2 = 6.315, P < 0.05), but not related to the histological type and Borrmann type (c2 = 5.391 and c2 = 2.228, respectively). Moreover, MVD in gastric cancer tissues was significantly higher than that in the normal mucosa (65.49 +/- 20.64 vs 36.21 +/- 18.47, t/F = 7.53, P < 0. 05). MVD was related to the histologic type and metastasis (t/F = 3.68 and t/F = 4.214, respectively, P < 0. 05), but not related to the depth of invasion and Borrmann type (t/F = 0.583 and t/F = 0.459, respectively). MVD in COX-2-positive tissues was markedly higher compared to COX-2-negative tissues, indicating a positive correlation between COX-2 expression and MVD (t = 13.12, P < 0. 05).

CONCLUSION

Tissue microarray (TMA) is a powerful tool for rapid identification of the molecular alterations in gastric cancer. COX-2 expression, via inducing angiogenesis, may play an important role in gastric carcinogenesis. It could be served as a determinant factor for clinical prognosis and curative effect.