Epidemiology

Certain IBD patients at greater colorectal cancer risk

Last Updated: 2007-05-03 18:45:44 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Numerous factors are associated with an increased risk of colorectal neoplasia in patients with inflammatory bowel disease (IBD), according to US and Danish researchers.

"We combined two well-characterized population-based inception cohorts of IBD to perform this nested case-control study," investigator Dr. Edward V. Loftus Jr. told Reuters Health.

"We found that dysplasia and cancer were generally associated with primary sclerosing cholangitis, as well as various markers of disease activity."

As reported in the April issue of the American Journal of Gastroenterology, Dr. Loftus of the Mayo Clinic, Rochester, Minnesota and colleagues studied 43 IBD patients with neoplasias and 102 matched controls.

Among the factors that increased the risk of neoplasia were primary sclerosing cholangitis (odds ratio, 6.9), the proportion of disease course with clinically active disease (odds ratio, 1.2 per 5% increase), and having a year or more of continuous symptoms (odds ratio, 3.2). There was a borderline association with the median number of small-bowel X-rays (odds ratio, 1.3).

"The findings," continued Dr. Loftus, "fit in nicely with emerging data that the degree of chronic inflammation of the colon is a risk factor for dysplasia and cancer in the setting of IBD. It also confirms previous work that primary sclerosing cholangitis is an important risk factor."

Frequent physician visits did not lower the risk of developing neoplasia. Furthermore, Dr. Loftus added, "We had expected to see a protective effect of 5-aminosalicylate medications and colonoscopy, but did not."

Am J Gastroenterol 2007;102:829-836.