Crohn's disease ups risk of intestinal cancer

Patients with Crohn's disease - an inflammation of the digestive tract that affects a half million Americans, many age 15 to 35 years - face a higher risk of intestinal cancer, according to a new report.

"Patients with Crohn's disease appear to be at increased risk of both colorectal cancer and small bowel cancer," said Dr. Tine Jess from Herlev University Hospital, Copenhagen, Denmark.

Jess and colleagues conducted a meta-analysis of the overall risk for colorectal cancer and small bowel cancer in Crohn's disease patients, compared with the expected risks in age- and gender-matched background populations.

The overall risk for colorectal cancer was 1.9-fold higher for Crohn's patients than for patients without Crohn's, the authors report. The elevated risk for rectal cancer (1.4-fold) was somewhat lower than for colon cancer (2.5-fold).

The elevated risk of colorectal cancer applied only to Crohn's disease patients with colonic Crohn's disease or iliocolonic Crohn's disease and not to patients whose disease was restricted to the ileum.

The risk for small bowel cancer was more than 27 times higher among patients with Crohn's disease than among others, the researchers note.

Jess cautioned that these results are based on cohort studies of patients diagnosed back to the 1940s, "and the treatment policy has changed several times since then."

"The recent introduction of immunosuppressive drugs in the treatment of patients with Crohn's disease may likely have diminished the risk of intestinal cancer by enhancing the control of the intestinal inflammation in these patients, although the risk of other malignancies may have increased simultaneously."

SOURCE: American Journal of Gastroenterology December 2005.