S2585 De Novo Colorectal Cancer Following Liver Transplantation for Primary Sclerosing Cholangitis With or Without Inflammatory Bowel Disease

Introduction: Primary Sclerosing Cholangitis (PSC) is an immune-mediated biliary disorder and often associated with inflammatory bowel disease (IBD). Liver transplantation (LT) is the treatment of choice for patients with end-stage PSC. After LT, the risk of de novo colorectal cancer (CRC) remains high, with many contributing factors such as long-term immunosuppressive therapy and concomitant IBD. While PSC with IBD is a known CRC risk factor, its impact in PSC alone is unclear. We aimed to evaluate the incidence of CRC in PSC patients with/without IBD using a national database. Methods: This cohort study used the United Network Organ Sharing (UNOS) data. We evaluated all adult LT recipients from 1997–2023. Patients with PSC were categorized into 2 groups: PSC with IBD and PSC without IBD. De novo CRC was defined as CRC occurring at least 1-year after LT. The primary endpoint was the cumulative incidence of CRC, with death was treated as a competing risk. We fit multivariable Cox proportional hazards regression models to evaluate the association. Results: A total of 137,742 patients were included, consisting of 4,572 PSC patients with IBD and 2,818 without IBD. Among the PSC LT recipients, 101 developed CRC, with 77 in the PSC with IBD group and 24 in the PSC without IBD group. In multivariate Cox proportional hazards regression analysis, PSC patients with IBD were at significantly increased risk of CRC compared to the non-PSC group (aHR 4.79, 95% CI 3.56–6.43, P < 0.001). PSC patients without IBD also had an increased risk of CRC (aHR 1.99, 95% CI 1.18–3.37, P = 0.01). PSC patients without IBD also demonstrated a significantly higher risk of CRC compared to the non-PSC group. Conclusion: Our study demonstrated an elevated CRC risk in PSC patients with IBD compared to non-PSC LT recipients. PSC patients without IBD also demonstrated a higher CRC risk compared to the non-PSC LT recipients. Current guidelines recommend annual colonoscopy for PSC patients with IBD. Our findings suggest that LT recipients for PSC, independent of IBD, warrant more frequent CRC screening than the general population.