• UC complicated by PSC is associated with an increased risk of CRC.
• Alteration in the composition of colonic bile acids has been implicated. This may also account of the disproportionately higher incidence of right sided colon cancers in PSC.
• The prevalence of UC in PSC patients approaches 90%. Thus all patients with PSC should have a flexible sigmoidoscopy. Colonic biopsies should be done even if the mucosa looks macroscopically normal.

Discuss surveillance?

Annual colonoscopy is recommended by British Society of Gastroenterology. The annual surveillance should be done regardless of the duration of colitis. Surveillance should continue after liver transplantation too.

If the biopsies reveal indefinite dysplasia, repeat colonoscopy should be done every 6-12 months. Colectomy should be recommended for high grade dysplasia. Colectomy should also be considered in low grade dysplasia. An alternative is repeat colonoscopy in 3-6 months to confirm the diagnosis. If there are multiple sites of low grade dysplasia or multiple inflammatory polyps that preclude adequate surveillance, colectomy should definitely be recommended.

Discuss chemoprevention?

Ursodeoxycholic acid (UDCA) may be chemoprotective against the development of colon cancer