Trends in incidence, treatments, and clinical outcomes of cholangiocarcinoma diagnosed in British Columbia, Canada, from 2005 through 2019.

522 Background: While only accounting for 3% of gastrointestinal malignancies, cholangiocarcinoma (CC) has poor prognosis. New targeted therapies are on the horizon and understanding the potential size of the population eligible for such therapies is of importance. Contemporary incidence and outcomes in Canada have not been studied. Methods: Patients diagnosed with CC between 2005-2019 in British Columbia were identified using the BC Cancer Registry. Patient characteristics, treatments received and outcomes were collected and analyzed. Results: A total of 1520 patients were identified. Median age at diagnosis was 69 (interquartile 61-76) and 52% were female, 594 patients presented with localized disease (39%) of whom 416 had disease recurrence. The proportion of intrahepatic CC (ICC) rose from 17% in 2005-2009 to 44% in 2015-2019 while the incidence of extrahepatic (ECC) and gallbladder (GB) cancers followed populational trends. More patients with ICC had stage IV cancer at the time of diagnosis (64% vs 43% for ECC and 45% for GB, p<0.01). Treatments received are shown in the table. Among 1086 patients with recurrent or metastatic disease, 54% and 14% respectively received first- and second-line chemotherapy. Overall survival (OS) was 13.7 months [HR 0.43 (95% CI 0.37-0.49)] with 1 line of treatment and 21.3 months with 2 lines [HR 0.30 (95% CI 0.24-0.37)], compared to 4.8 months with best supportive care. On multivariate analysis, ECOG, first and second-line treatment and liver-directed therapy remained associated with improved outcomes while tumor site or time period did not. Conclusions: The incidence of CC is rising and most patients present with advanced disease. Treatment attrition is high and few patients receive second line therapies. The outcomes of patients receiving first line, second line and liver-directed therapies are significantly better than those receiving supportive care only. Understanding contemporary trends in presentation and treatment patterns is essential as we consider strategies to improve implementation and access of emerging novel therapies in this setting. [Table: see text]