Utility of MRCP in surveillance of primary sclerosing cholangitis associated hepatobiliary malignancy: 15 year experience at a single institution in Ontario, Canada

Objective: Magnetic resonance cholangiopancreatography (MRCP) is used for the surveillance of primary sclerosing cholangitis (PSC) and its associated complications. The time interval gap for subsequent follow-up MRCP is variable depending on clinical practice patterns, therefore this study was done to assess the MRCP follow-up strategy used in our institution for screening PSC-associated hepatobiliary malignancies. Materials and methods: This retrospective observational cohort included MRCP studies in adult patients, with clinical and radiological diagnosis of PSC over the past 15-year period between January 1, 2003 to December 31, 2018. The study population was grouped based on the presence and absence of PSC-associated malignancy. The frequency of MRCP follow-up was compared between the groups to look for MRI ordering trends in surveillance for PSC-associated complications. Results: The overall median interval follow-up with MRCP was 14 months. The median follow-up interval in cases with PSC-associated malignancy was 6.0 months, compared to 13.1 months in the PSC group without malignancy (p 0.013). During the study period, the PSC-associated malignancy group had a median number of 7.5 scans, while the no malignancy group had a median number of 4 scans. Three patients (3/10, 30%) developed hepatobiliary malignancies within the first year of clinical diagnosis of PSC. The most common malignancy associated with PSC was cholangiocarcinoma (4.6%,7/10). Other PSC-associated malignancies included carcinoma gallbladder (1.3%,2/10), and hepatocellular carcinoma (0.6%,1/10). The median age of PSC associated malignancies was 56 (IQR 15) and higher compared to median age of PSC group without malignancies 46 (IQR 25.5), p 0.035. Conclusion: The median interval for subsequent follow-up MRCP in our study cohort was 14 months. One-third of PSC-associated hepato-biliary malignancies developed within the first year of clinical diagnosis of PSC, and the risk of PSC-associated hepato-biliary malignancy is constant after the first year.