Treatment and survival of resected and unresected distal cholangiocarcinoma: a nationwide study

Background: Population-based data on distal cholangiocarcinoma (DCC) from the Western world are not available, albeit essential to identify areas for improvement. This study investigated the incidence, treatment and outcomes, including time trends and predictors for survival, in a nationwide cohort of DCC. Methods: This is a retrospective cohort study of patients diagnosed with DCC (2009-2016) derived from the Netherlands Cancer Registry. Overall survival (OS) and its predictors were analyzed using Kaplan-Meier and Cox regression analysis. Time trends (2009-2012 versus 2013-2016) were assessed. Results: Overall, 1338 patients with DCC were included, with 1-, 3- and 5-year OS of 46%, 18%, and 11%. Incidence of DCC was 0.55-0.90 per 100.000 per year. Median OS was 10.4 months across all stages; 21.9 months for resected (n = 620, 46.3%), 6.7 months for unresected nonmetastatic (n = 445, 33.3%), and 3.6 months for metastatic DCC (n = 273, 20.4%) (p < .001). After resection, 30-day mortality was 4.8% and 90-day mortality 7.7%. Patients with metastatic DCC who received chemotherapy (n = 78, 28.6%) had a median OS of 8.2 versus 2.8 months for those not treated (p < .001). Over time, resection rates (53.6% to 61.7%, p = .008) and use of palliative chemotherapy in metastatic DCC (22.3% to 32.9%, p = .05) increased, without improvement in OS (10.3 vs 10.6 months, p = .55). Independent poor prognostic factors for OS in resected disease were increasing age, pT3/T4 stage, higher lymph node ratio, poor differentiation, and R1 resection. Conclusions: In a nationwide cohort of DCC, resection rates and the use of chemotherapy increased whereas OS remained stable at 10.4 months.