Prolonged use of aspirin and/or non-steroidal anti-inflammatory drugs induces a partial regression of either sporadic adenomas or adenomas in adenomatous polyposis coli (APC), but also their emergence and colonic cancer development in sporadic adenomas. Specific inhibitors of cyclooxygenase of type 2 (Cox2) induce less upper and lower digestive tract adverse events that non-specific anti-inflammatory drugs. This better tolerance might allow a long-lasting use in patients with APC. At time, we don't know if such treatments are able to prevent the development of cancer in the rectum or duodenum of these patients. In this paper we will discuss the scientific proofs and potential interest of Cox2 inhibitors in the treatment of PAF.