Geographic Disparities in Referral Rates and Oncologic Outcomes of Intrahepatic Cholangiocarcinoma: A Population-Based Study

Background: Intrahepatic cholangiocarcinoma (ICC) is a rare cancer. Patients in rural areas may face reduced access to advanced treatments often only available at referral centers. We evaluated the association of referral center treatment with treatment patterns, outcomes, and geography in patients with ICC. Methods: We queried the Oregon State Cancer Registry for ICC between 1997 and 2016, collecting clinicopathologic, demographic, and oncologic data. Patients were classified by treatment at a referral center or non-referral center. ‘Crowfly’ distance to the nearest referral center (DRC) was calculated. Outcomes were evaluated using Kaplan–Meier, Cox proportional hazards modeling, and logistic regression. Results: Over 20 years, 740 patients with ICC had a median age of 66 years. Slightly more than half (n = 424, 57%) were non-referral center treated and 316 (43%) were referral center treated. Referral center treatment increased over time (odds ratio [OR] 1.03/year, p < 0.05). Referral center-treated patients had improved overall survival in all patients (median 9 vs. 4 months, p < 0.001), in the non-metastatic group (median 13 vs. 6 months, p < 0.001), and in patients not receiving liver resection (median 6 vs. 3 months, p < 0.05). On multivariable analysis, referral center-treated patients more often underwent chemotherapy, resection, or radiation (all p < 0.05). Increasing DRC (OR 0.98/20 km, p < 0.05) was independently associated with non-referral center treatment. Conclusion: Patients with ICC who are evaluated at a referral center are more likely to receive treatments associated with better oncologic outcomes, including patients who are not managed with hepatic resection. Increasing the DRC is associated with treatment at a non-referral center; interventions to facilitate referral, such as telemedicine, may lead to improved outcomes for patients with ICC in rural states.