Navigating Neoplasm Risk in Inflammatory Bowel Disease and Primary Sclerosing Cholangitis.

(1) Background and Aims: Patients with inflammatory bowel disease (IBD) and primary sclerosing cholangitis (PSC) face a significantly increased risk of malignancies, including a 10-fold higher risk for colorectal cancer (CRC) and a lifetime risk for cholangiocarcinoma (CCA) exceeding 20%. The mechanisms underlying this elevated risk remain elusive. This review consolidates recent findings on cancer risk in PSC-IBD patients, focusing on molecular pathways, diagnostic innovations, and prevention strategies. (2) Methods: A comprehensive PubMed search was performed to identify studies published through to March 2025 on oncogenic processes, molecular mechanisms, and advancements in diagnostic and preventive strategies for CRC and CCA in PSC-IBD patients. (3) Results: Surveillance guidelines recommend an annual colonoscopy for CRC and imaging combined with CA 19-9 monitoring for CCA. Recent studies highlight the role of molecular alterations, including epigenetic modifications, in tumorigenesis. Advances in molecular diagnostics, imaging, and endoscopic technologies are improving the accuracy and timeliness of cancer detection. (4) Conclusions: PSC-IBD patients remain at high risk for CRC and CCA, emphasizing the need for vigilant surveillance and advanced prevention strategies. Advances in early detection and precision diagnostics offer new opportunities to reduce the cancer burden in this high-risk population.