Abstract
Patients with inflammatory bowel disease (IBD) have increased risk of colorectal cancer
(CRC). The risk for CRC is positively correlated to the duration of disease, extent
of colonic involvement, and severity of inflammation. After 8 to 10 years of IBD diagnosis,
the risk for CRC rises substantially and screening colonoscopy is recommended. Surveillance
colonoscopy interval ranges from 1 to 5 years depending on patient and disease-specific
risk factors. IBD patients with high risk factors such as having concomitant primary
sclerosing cholangitis, moderate-to-severe inflammation, first-degree relative with
CRC at early age, or history of invisible dysplasia or high-risk visible dysplasia
should undergo surveillance colonoscopy in 1 year. Meanwhile, those with minimal colonic
involvement or ≥2 consecutive unremarkable examinations while in continuous remission
may consider extending the surveillance interval to 5 years. Advance in colonoscopy
technique such as chromoendoscopy using dyes and/or image digital processing (virtual
chromoendoscopy) may enhance dysplasia detection and is the preferred method for IBD
surveillance. In the era of high-definition colonoscope, the practice of obtaining
extensive biopsies throughout the colon remains controversial but is generally recommended
to improve the detection rate of invisible dysplasia. Endoscopic surveillance in IBD
has been shown to result in earlier detection of CRC and improved prognosis.
Keywords
inflammatory bowel disease - colorectal cancer - risk factors - surveillance - chromoendoscopy
