HONOLULU — Two good reasons exist for all ulcerative colitis patients to be on 5-aminosalicylate long term, Bret A. Lashner, M.D., said at the annual meeting of the American College of Gastroenterology.
One is that the drug helps maintain remission. That's common knowledge. But 5-ASA also may reduce the risk of developing colorectal cancer, said Dr. Lashner, director of the Center for Inflammatory Bowel Disease at the Cleveland Clinic Foundation.
Evidence for a chemopreventive effect of 5-ASA is “somewhat weak,” he conceded. There have been five studies addressing the issue, all observational. Three proved positive, and two showed no effect.
But a recent metaanalysis by Fernando S. Velayos, M.D., and colleagues at the University of California, San Francisco, that included these five studies as well as four others looking at the combined end point of colorectal cancer or dysplasia, concluded 5-ASA was indeed protective against colorectal cancer. The drug was associated with a 49% reduction in relative risk. It was also associated with an identical 49% reduction in the risk of colorectal cancer/dysplasia (Am. J. Gastroenterol. 2005;100:1345–53).
“We now know from work at the University of Chicago that patients don't take this medication the way they should. Adding into your practice the advice that 5-ASA not only prevents recurrence but might help decrease the risk of cancer or dysplasia might get patients to take their medicine more often,” Dr. Lashner said.
Two other agents are supported by evidence of efficacy for primary chemoprevention of colorectal cancer in ulcerative colitis patients. One is folic acid at 0.4–1.0 mg/day. Only one of three epidemiologic studies showed a statistically significant benefit, but since folic acid is safe and inexpensive, it is something that ulcerative colitis patients ought to routinely take long term, Dr. Lashner said.
The other agent is ursodeoxycholic acid, which in two studies showed efficacy in inflammatory bowel disease patients with primary sclerosing cholangitis, he said. The dose is 1,200 mg/day.