대한대장항문학회

Purpose: Several studies indicate that nonsteroidal anti- inflammatory drugs including aspirin and sulindac reduce the risk of colon cancer. Futhermore, nonsteroidal anti-inflammatory drugs that inhibit the cyclooxygenase (COX) are shown to<br>inhibit<br>the<br>development colon cancer in animal models of carcinogenesis. COX-1 is constitutively expressed to fulfill its beneficial housekeeping roles. COX-2 is not constitutively expressed by most normal tissues, but it is rapidly induced by certain<br>inflammatory<br>cytokines, tumor promoters, growth factors and oncogenes. The purpose of this study is to evaluate the role of COX-2 in colorectal carcinoma development and the correlation between COX-2 expression and tumor angiogenesis and p53 overexpression.<br>Methods: Immunohistochemical analyses using antibodies against COX-2, factor VIII-related antigen, vascular endothelial growth factor (VEGF) and p53 were carried out on archival specimens of 15 colorectal adenoma and 41 adenocarcinoma.<br>Results: COX-2 expression was increased in 5/15 (33.3%) adenomas and 24/41 (58.5%) adenocarcinomas. COX-2 expression in adenocarcinoma was nearly significantly higher than in adenoma (P=0.050). In adenocarcinoma, COX-2 expression was increased in<br>early<br>cancer (TNM stage) (P=0.028) and well differentiated tumor (P=0.029). COX- 2 expression was not correlated with VEGF expression, microvessel density and p53 overexpression.<br>Conclusions: These findings indicate that enhanced expression of COX-2 occurs early during colorectal cancer progression. However, further investigations are needed to evaluate the relationship of COX-2 and tumor angiogenesis using other<br>laboratory<br>methods.<br>