Cyclooxygenase inhibitors in the chemoprevention of colorectal cancer.

The long-term use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a decreased risk for colorectal cancer. A major molecular target for cancer chemoprevention by these agents is the cyclooxygenase- 2 (COX-2) isoenzyme, although other molecular pathways can not be excluded. Data from both human and animal studies suggest that COX-2 is an early event of colorectal carcinogenesis. The NSAIDs, in the particular the newly developed COX-2 selective inhibitors, suppress colorectal tumor development in rodents and significantly reduce the number of colorectal polyps in patients suffering from familial adenomatous polyposis coli. In this paper current opinions regarding the role of COX inhibitors in colorectal cancer prevention are reviewed. Some perspectives derived from experimental and clinical studies, that might improve future approaches in the prevention of this malignancy, are also considered.