Expression of cyclooxygenase-2 and inducible nitric oxide synthase correlates with tumor angiogenesis in endometrial carcinoma

The present study evaluated the significance of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in 30 patients with endometrial carcinoma and the relationship of those molecular markers to tumor characteristics and microvessel density (MVD). Immunohistochemical expression of COX-2, iNOS, and CD34 was analyzed on paraffin-embedded tissue sections. The COX-2 and iNOS positive rates were 66.7% and 73.3%, respectively. The level of COX-2 expression was higher in grade II tumors than in grade III tumors (p<0.05). The percentage of iNOS positivity was higher in patients with deep myometrial invasion than in patients without or less than 50% myometrial invasion (p<0.05). There was significant correlation between positive COX-2 and positive iNOS expression (r=0.601, p<0.001). Both COX-2 and iNOS were significantly correlated with MVD (r=0.02 p<0.05; r=0.599 p<0.0001, respectively). The present findings suggest that combined expression of COX-2 and iNOS may play an important role in development and invasion of endometrial cancer and that this could be partially attributable to modulation of angiogenesis by COX-2 and iNOS.