Risk of colorectal cancer in patients with primary sclerosing cholangitis and concomitant inflammatory bowel disease compared with primary sclerosing cholangitis only

Aim: Primary sclerosing cholangitis (PSC) increases the risk of colorectal cancer (CRC) in inflammatory bowel disease (IBD) patients; however, there is a paucity of literature to suggest PSC alone as an independent risk factor for CRC. We aimed to determine if PSC is an independent risk factor for CRC in a large tertiary care medical center. Optimizing screening intervals is of great importance, given the burden and risks associated with a lifetime of colonoscopy screening. Methods: This retrospective cohort study consists of patients diagnosed with PSC preceding IBD (PSC-IBD) and PSC-only before January 6, 2023 from a large, tertiary, academic medical center. Patients diagnosed with IBD concurrently or before PSC were excluded to reduce IBD's impact on CRC risk. Demographic data and colonoscopy findings were collected and assessed. Results: Overall, 140 patients from all NYU Langone Health clinical settings were included. Patients with PSC-IBD were more likely to be diagnosed with CRC (23.3% vs. 1.8%, p < 0.01) and either low-grade or uncharacterized dysplasia (16.7% vs. 0.0%, p < 0.01) compared with those with PSC-only. Among PSC-only patients, the estimated CRC risk was significantly elevated compared with that expected of the standard NYU Langone population (SIR 9.2, 95% CI 1.1, 33.2). Conclusions: Our study revealed a significantly heightened CRC risk in PSC-IBD patients compared with those with PSC-only. Importantly, individuals with PSC-only also face a greater CRC risk compared with the general population. Individuals with PSC-alone may require extended screening and surveillance colonoscopy intervals compared with those with PSC-IBD, yet still require more frequent monitoring than screening guidelines recommend for the general population.