Adjuvant therapy is associated with improved survival after curative resection for hilar cholangiocarcinoma: A multi-institution analysis from the U.S. extrahepatic biliary malignancy consortium

Background: Curative-intent treatment for localized hilar cholangiocarcinoma (HC) requires surgical resection. However, the effect of adjuvant therapy (AT) on survival is unclear. We analyzed the impact of AT on overall (OS) and recurrence free survival (RFS) in patients undergoing curative resection. Methods: We reviewed patients with resected HC between 2000 and 2015 from the ten institutions participating in the U.S. Extrahepatic Biliary Malignancy Consortium. We analyzed the impact of AT on RFS and OS. The probability of RFS and OS were calculated in the method of Kaplan and Meier and analyzed using multivariate Cox regression analysis. Results: A total of 249 patients underwent curative resection for HC. Patients who received AT and those who did not had similar demographic and preoperative features. In a multivariate Cox regression analysis, AT conferred a significant protective effect on OS (HR 0.58, P = 0.013), and this was maintained in a propensity matched analysis (HR 0.66, P = 0.033). The protective effect of AT remained significant when node negative patients were excluded (HR 0.28, P = 0.001), while it disappeared (HR 0.76, P = 0.260) when node positive patients were excluded. Conclusions: AT should be strongly considered after curative-intent resection for HC, particularly in patients with node positive disease.