대한대장항문학회

PURPOSE: Recently, it has been recognized that both cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) produce important endogeneous factors of human tumor progression. The aims of this study is to investigate the correlation between<br>the expression of COX-2 and iNOS and to assess the clinicopathological significance of COX-2 and iNOS expression in patients with colorectal cancer. METHODS: One hundred and five patients, who underwent curative resection of colorectal cancer from 1994<br>to 1997 were analyzed retrospectively. The monoclonal antibody to the COX-2 and iNOS were used for the immunohistochemical analysis. RESULTS: In 105 patients the COX-2 and iNOS positive rate were 86.7% and 69.5% respectively. There was significant<br>correlation between COX-2 and iNOS expression (r=0.378, P??.01), that is, the lesions which expressed high level of COX-2 also expressed iNOS highly. The proliferation index (Ki-67 labeling index) was correlated with iNOS (P=0.013), and the<br>microscopic differentiation with COX-2 (P=0.004). However, the expression of COX-2 and iNOS proteins did not correlate with any other clinicopathological parameters including patient survival. CONCLUSIONS: Although the pattern of positive expression was<br>similar in both enzymes, the expression of both enzymes was not related to prognosis in patients with colorectal cancer. But COX-2 and iNOS seems to have a role not only in carcinogenesis but also tumor cells proliferation. To evaluate the exact role of<br>these enzymes, further studies of the apoptosis and cancer metastasis and of links between the cancer related factors of COX-2 and iNOS are warranted.<br>