Primary sclerosing cholangitis (PSC) is a relatively uncommon cause of chronic liver disease, but frequently leads to end-stage liver disease and is a major indication for liver transplantation; The worldwide prevalence of PSC has been estimated to be up to 8,5 cases per 100000,, However, PSC is common among patients with inflammatory bowel disease, with an estimated prevalence of 3-5%. It has long been recognized that chronic ulcerative colitis and Crohn's disease of the colon are associated with an increased risk of colon cancer. Recent studies have found that there is a significantly increased risk of colon cancer among patients with PSC, A large study from Sweden found that cumulative risk of developing colorectal dysplasia or cancer was 50% after 25 years of disease, compared to 10% among patients with ulcerative colitis (UC) alone1; similar results were found in two other studies2. Other risk factors for colorectal neopla-sia in chronic UC include age, presence of pancolitis, duration of disease and early age at diagnosis. The pathogenesis of colon cancer in UC has been linked to a 'dysplasia to carcinoma sequence'; it has been postulated that genetic factors, as well as dietary and other environmental influences, contribute to the pathogenesis of colon cancer in UC with and without PSC, Given the high incidence of colon cancer in UC associated with PSC, the difficulty in detecting cancer at an early stage, and the high mortality associated with this disease, there is a need for preventive therapies against colon cancer. There is already a body of work examining the utility and efficacy of multiple such agents for chemopre-vention of colon cancer in patients without UC, Such therapies can be classified as nutritional interventions and chemopreventive agents3.
展开▼
