Crohn's disease is associated with small bowel cancer, while risk of colorectal cancer is less clear.
Dr Canavan and colleagues from England ascertained the combined estimates of relative risk of these cancers in Crohn's disease.
The team searched MEDLINE to identify relevant papers.
The research team exploding references to identify additional publications.
When two papers reviewed the same cohort, the later study was used.
The researchers found that the overall colorectal cancer relative risk in Crohn's disease was 2.5.
The relative risk was 4.5 for patients with colonic disease, and 1.1 in patients with ileal disease.
|Overall colorectal cancer relative risk in Crohn's disease was 2.5|
|Alimentary Pharmacology & Therapeutics|
The team observed a reduction in relative risk over the past 30 years.
Subgroup analysis showed Scandinavia had significantly lower colorectal cancer relative risk than the UK and North America.
The team found that the 10-year cumulative risk of colorectal cancer following diagnosis of Crohn's disease is 3 %.
The researchers showed that the relative risk of small bowel cancer in Crohn's disease is 33.
Small bowel cancer relative risk has not significantly reduced over the last 30 years.
Dr Canavan's team concluded, “Relative risk of colorectal and small bowel cancers are significantly raised in Crohn's disease.”
“Cumulative risk of colorectal cancer of 3 % at 10 years suggests a potential benefit from routine screening.”
“However, the value of screening requires rigorous appraisal.”