Aspirin and Colon Cancer — Targeting Prevention?

The compelling evidence that chronic use of aspirin or certain nonsteroidal antiinflammatory drugs (NSAIDs) can substantially lower the risk of colon cancer has important implications, especially because colon cancer is the second leading cause of cancer death. Aspirin and nonselective NSAIDs each inhibit the generation of prostaglandins by inhibiting the two cyclooxygenase (COX) enzymes that initiate prostaglandin synthesis, COX-1 and COX-2. NSAIDs that are selective for COX-2 also inhibit the generation of prostaglandins. COX-1 is constitutively expressed in the colon, but COX-2 is inducible and markedly up-regulated in many colon cancers. Interventional trials have shown a decreased risk of the . . .