http://www.medscape.com/viewarticle/467896 (Free to view, but you must sign in)
NEW YORK (Reuters Health) Jan 28 - Contrary to previous reports, new study findings suggest that treatment with 5-aminosalicylate (5-ASA) does not prevent colorectal cancer in patients with inflammatory bowel disease.
In studies in the UK and Denmark, Dr. Charles N. Bernstein and colleagues from the University of Manitoba in Winnipeg, Canada note that 5-ASA use has been linked to a reduced risk of cancer in patients with ulcerative colitis and Cohn's disease. However, it is possible that patient selection bias may have influenced the results.
To investigate, the researchers report in December issue of The American Journal of Gastroenterology, that they compared 25 inflammatory bowel disease patients who were diagnosed with colon cancer in Manitoba between 1997 and 2000 and 348 matched patients who did not develop cancer.
The investigators suggest that the main advantage of this study was that "it is population-based and is not sampling only those subjects who present to referral centers,"
Among patients exposed to 5-ASA, the average duration of use and the daily dose were similar in each group. In fact, the researchers note that the cancer patients were more likely to have been exposed to 5-ASA than were comparison patients. However, the difference was not statistically significant.
The researchers conclude that 5-ASA does not reduce the risk of colon cancer in such patients. However, they add that further studies with a larger sample size and longer duration of use are needed to completely rule out an anti-cancer effect.
Am J Gastroenterol 2003;98:2784-2788.