Comparing Survival of Perihilar Cholangiocarcinoma After R1 Resection Versus Palliative Chemotherapy for Unresected Localized Disease

Background: Resection of perihilar cholangiocarcinoma (pCCA) is a complex procedure with a high risk of postoperative mortality and early disease recurrence. The objective of this study was to compare patient characteristics and overall survival (OS) between pCCA patients who underwent an R1 resection and patients with localized pCCA who received palliative systemic chemotherapy. Methods: Patients with a diagnosis of pCCA between 1997-2021 were identified from the European Network for the Study of Cholangiocarcinoma (ENS-CCA) registry. pCCA patients who underwent an R1 resection were compared with patients with localized pCCA (i.e., nonmetastatic) who were ineligible for surgical resection and received palliative systemic chemotherapy. The primary outcome was OS. Results: Overall, 146 patients in the R1 resection group and 92 patients in the palliative chemotherapy group were included. The palliative chemotherapy group more often underwent biliary drainage (95% vs. 66%, p < 0.001) and had more vascular encasement on imaging (70% vs. 49%, p = 0.012) and CA 19.9 was more frequently >200 IU/L (64 vs. 45%, p = 0.046). Median OS was comparable between both groups (17.1 vs. 16 months, p = 0.06). Overall survival at 5 years after diagnosis was 20.0% with R1 resection and 2.2% with chemotherapy. Type of treatment (i.e., R1 resection or palliative chemotherapy) was not an independent predictor of OS (hazard ratio 0.76, 95% confidence interval 0.55-1.07). Conclusions: Palliative systemic chemotherapy should be considered instead of resection in patients with a high risk of both R1 resection and postoperative mortality.