Comparison of the effects of adjuvant concurrent chemoradiotherapy and chemotherapy for resected biliary tract cancer

BACKGROUND: Biliary tract cancers (BTC) have a poor prognosis even after curative resection because of frequent local and distant recurrences. Therefore, the importance of adjuvant therapy in BTC has been advocated to improve outcomes. However, the choice of adjuvant therapy is still controversial. The aim of this study was to compare the effects of adjuvant concurrent chemoradiotherapy (CCRT) and chemotherapy on resected BTC. METHODS: We analyzed 92 patients who had curatively resected BTC and had received adjuvant CCRT or chemotherapy from January 2000 to December 2017 at Keimyung University Dongsan Medical Center. RESULTS: Of the patients, 46 received adjuvant CCRT and 46 received adjuvant chemotherapy. The median recurrence-free survival (RFS) for the adjuvant CCRT and chemotherapy groups were 13.8 and 11.2 months (p = 0.014), respectively. The median overall survival (OS) for the adjuvant CCRT and chemotherapy groups were 30.1 and 26.0 months (p = 0.222), respectively. Adjuvant CCRT had significantly better RFS and numerically higher OS than did chemotherapy. For subgroups with no lymph node (LN) involvement (RFS p = 0.006, OS p = 0.420) or negative resection margins (RFS p = 0.042, OS p = 0.098), adjuvant CCRT led to significantly longer RFS and numerically higher OS than did chemotherapy. For multivariate analysis, the pattern of adjuvant treatment (chemotherapy vs. CCRT, p = 0.004, HR 2.351), histologic grade (poor vs. well, p = 0.023, HR 4.793), and LN involvement (p = 0.028, HR 1.912) were the significant prognostic factors for RFS. CONCLUSIONS: Our study demonstrated the superiority of adjuvant CCRT over chemotherapy for improving RFS in curatively resected BTC.