Adjuvant Therapy Is Associated With Improved Survival in Resected Perihilar Cholangiocarcinoma: A Propensity Matched Study

Background: There are limited well-controlled studies that conclusively demonstrate a benefit of adjuvant therapy in resected perihilar cholangiocarcinoma. Most studies include all biliary tract tumors as one entity despite the heterogeneity of these diseases. Methods: We identified patients with resected perihilar cholangiocarcinoma from the National Cancer Database between 2006 and 2013. Patients who received adjuvant therapy (AT) were compared to an observation (OB) cohort by propensity score matching. Results: We identified 1846 patients: 1053 patients (57%) in the OB group, and 793 (43%) in the AT group. Patients who received adjuvant therapy were more likely to be younger, have a higher rate of private insurance, have higher T and N stage tumors, and were more likely to have positive resection margins. After 1:1 propensity score matching, 577 OB group patients were compared with 577 AT group patients. The AT cohort was associated with better overall survival compared with the OB cohort (hazard ratio [HR] 0.73; 95% confidence interval [CI] 0.64–0.83). The median survival was 29.5 and 23.3 months for the AT and OB groups, respectively (P < 0.01). Subgroup analysis demonstrated a survival advantage for adjuvant therapy in disease with positive resection margins (HR 0.53; 95% CI 0.42–0.67). Conclusions: Adjuvant therapy is associated with improved survival in resected perihilar cholangiocarcinoma, especially in disease with positive resection margins. This study supports the use of adjuvant therapy in high-risk patients.