Ulcerative colitis is an inflammatory disease of the bowel. Its cause is unknown, but there appears to be a genetic predisposition for the disease. People with ulcerative colitis have a higher risk of developing colon cancer than people without the disease. The risk depends on how long a person has ulcerative colitis and how extensive it is. If the ulcerative colitis is limited to the rectum, the risk is not much different from the average. If however a person has widespread colitis, the risk may be 30 times higher than the general population.
Aspirin and the other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (also known as Motrin) and naproxen (also known as Aleve or Naprosyn) and the newer COX-2 drugs (Vioxx, Celebrex and others) all block an enzyme system called cyclooxygenase-2. This enzyme system is the cause of pain and inflammation, and also looks like it is involved in the growth of colon cancer cells. Large population-based studies have shown that use of NSAIDs and the newer COX-2 inhibitors are associated with a decreased colon cancer risk. We don't know yet what the right dose is or how long people should take the drugs, and studies are going on to try to find the right dose. Most studies have used large doses of these drugs. The 100 mg dose of ibuprofen is well below the dose that has been used in clinical studies. Because of the large dose used in the studies, side effects are a problem. Most experts limit the routine use of these drugs in the prevention of colon cancer to people who have had a precancerous or cancerous polyp removed from their colons. Regularly scheduled colonoscopy is important to screen for early signs of colon cancer.
We don't know if giving people with ulcerative colitis NSAIDs will reduce their risk of colon cancer. And many people with ulcerative colitis do not tolerate the NSAIDs.
http://digestive.niddk.nih.gov/ddiseases/pubs/colitis/#additional
Curr Cancer Drug Targets. 3(6):455-63, 2003 Dec.
Abstract
Colorectal cancer is a leading cause of cancer death throughout the world. The high prevalence and mortality associated with colon cancer make effective prevention and treatment an important public health and economic concern. Among the few agents known to inhibit colorectal tumorigenesis are the nonsteroidal anti-inflammatory drugs or NSAIDs, as well as newer agents such as celecoxib and rofecoxib. Both epidemiologic studies and investigations with animals show that these compounds possess marked anti-colorectal cancer properties. NSAIDS are widely known to be inhibitors of the cyclooxygenase (COX) enzymes, and it is thought that the chemopreventive effects of NSAIDs are at least in part due to this ability to inhibit COX. More recent studies, however, have suggested that NSAIDs may also exert anti-cancer effects through mechanisms independent of COX inhibition. COX-dependent and COX-independent mechanisms are not mutually exclusive and it is likely that both are involved in the biological activity of NSAIDs. [References: 112]
