BACKGROUND: Almost 10% of all patients with primary sclerosing cholangitis receive a diagnosis of Crohn's disease. Clinical characteristics and the risk of colon cancer or dysplasia in Crohn's disease and primary sclerosing cholangitis are less well examined than in ulcerative colitis.
OBJECTIVE: This study aimed to describe the clinical characteristics and risk of colorectal dysplasia and cancer in Crohn's disease in patients with primary sclerosing cholangitis.
DESIGN: This is a cohort study of all patients diagnosed with primary sclerosing cholangitis and colorectal Crohn's disease at Karolinska University Hospital, Huddinge, 1978 to 2006. Each patient was matched for age and the onset of Crohn's disease to 2 controls with colorectal Crohn's disease without liver disease.
SETTING: This study was conducted at a tertiary referral center.
PATIENTS: Twenty-eight patients (61% male) with primary sclerosing cholangitis and Crohn's disease and 46 patients (50% male) with Crohn's disease alone were studied. Clinical and endoscopic data were retrieved from medical records. Colonic biopsies from patients with primary sclerosing cholangitis were re-reviewed.
MAIN OUTCOME MEASURES: The primary outcome measured was the proportion of patients developing colorectal cancer.
RESULTS: Colorectal cancer or dysplasia developed in 9 patients with primary sclerosing cholangitis and in 3 controls. Patients with primary sclerosing cholangitis were more likely to develop colorectal dysplasia or cancer than controls (OR 6.78; 95% CI (1.65-27.9); P = .016). In patients with primary sclerosing cholangitis compared with controls, perianal fistulas occurred in 3% vs 33% (P = .003), bowel strictures occurred in 7% vs 30% (P = .03), and bowel surgery was performed in 18% vs 46% (P = .01). Histological granulomas were seen in 29% of the patients with primary sclerosing cholangitis compared with 43% in controls (P = not significant).
LIMITATIONS: This study was limited by its retrospective nature and the limited cohort.
CONCLUSIONS: Primary sclerosing cholangitis is a risk factor for the development of colorectal cancer and dysplasia in Crohn's disease. Obstructing disease and perianal fistulas are rare in primary sclerosing cholangitis and less common than in colonic Crohn's disease without liver disease.