B0018 - The Incidence of Cholangiocarcinoma Among Primary Sclerosing Cholangitis Patients Is Lower Than Previously Reported

Ronan Allencherril, MD, Rollin George, MD, Susan Hilsenbeck, PhD, Prasun Jalal, MD, MRCP
Baylor College of Medicine, Houston, TX

Introduction: Primary sclerosing cholangitis (PSC) is a chronic inflammatory disease involving the bile ducts with increased risk of cancer. The risk of cholangiocarcinoma (CCA) is of particular concern due to high mortality. The relative risk (RR) of CCA in PSC has been reported as high as 1,560 which may have been overestimated. The utility of current surveillance practice in PSC patients for CCA is unclear. We aimed to estimate the relative risk of CCA in PSC patients and effectiveness of surveillance for CCA in this

Methods: Data were retrospectively collected from electronic medical records of patients with a diagnosis of PSC at Baylor St. Luke’s Medical Center, Texas from 1998 to 2021. Patients with less than 1 year of follow up were excluded. Demographic data, risk factors, and CA-19-9 levels and biliary imaging records (every 6-12 months) were collected. The incidence of CCA in the study population was compared to the general population using cancer data from the Surveillance, Epidemiology, and End Results (SEER) Program.

Results: A total of 109 patients with imaging or biopsy evidence of PSC were included (Figure 1). With 532 person-years of follow up, the mean follow-up time was 4.9 (range=1.04-22.9) years per patient. Two patients developed CCA at an annual incidence rate of 0.38% (95% confidence interval [CI]= 0.04%-1.4%). The annual incidence in the SEER registry from 1998 to 2018 was 1.6 per 100,000 person years. The relative risk of CCA in the PSC population was 234.9 (95% CI= 26.4-848.2). IBD, diabetes, alcohol use, and tobacco use were not associated with CCA (p > 0.05). The two patients with CCA passed away 165 days and 359 days following the cancer diagnosis. Median peak CA-19-9 level in PSC patients without CCA was 24 U/mL. The two CCA patients had CA-19-9 levels of 3,060 and 21,197 U/mL. Of the two patients with CCA, neither were diagnosed by surveillance but after presenting with obstructive symptoms prompting additional workup.

Discussion: our study shows the risk of CCA among PSC patients is higher than the general population but lower than previously reported. Routine surveillance failed to detect CCA in our patients, who subsequently passed away within 1 year of cancer diagnosis, suggesting current surveillance practice with imaging and CA-19-9 may not help diagnose CCA or improve mortality. This study questions the current practices of CCA surveillance, but further investigation is warranted.




Disclosures:


Ronan Allencherril, MD, Rollin George, MD, Susan Hilsenbeck, PhD, Prasun Jalal, MD, MRCP. B0018 - The Incidence of Cholangiocarcinoma Among Primary Sclerosing Cholangitis Patients Is Lower Than Previously Reported, ACG 2022 Annual Scientific Meeting Abstracts. Charlotte, NC: American College of Gastroenterology.