Author(s): Kenya Yamanaka, Etsuro Hatano, Masashi Kanai, Shiro Tanaka, Keiichi Yamamoto
Background Surgical resection is the only curative treatment of biliary tract cancer (BTC). However, the prognosis of BTC remains unsatisfactory. The aim of this study is to evaluate the benefits of adjuvant gemcitabine chemotherapy for BTC. Methods We performed a historical cohort study that involved 198 patients who underwent R0 surgical resection. Patients who underwent major hepatectomy were administered biweekly intravenous gemcitabine at a dose of 800 mg/m2. Otherwise, patients were administered intravenous gemcitabine at a dose of 1,000 mg/m2 in 3 weekly infusions, which were followed by a 1-week pause. The primary outcome was overall survival. The hazard ratio (HR) of adjuvant chemotherapy was estimated by propensity score-stratified Cox regression that was adjusted for confounders. Results Forty patients received adjuvant chemotherapy. The HR of adjuvant chemotherapy was 0.47 [95 % confidence interval (CI) 0.28–0.95; P = 0.03]. Subgroup analysis showed that the survival benefits were possibly modified by lymph node positivity (HR 0.19; 95 % CI 0.07–0.58; interaction, P = 0.22), stage III (HR 0.11; 95 % CI 0.02–0.50; interaction, P < 0.01), intrahepatic cholangiocarcinoma (ICC) (HR 0.09; 95 % CI 0.01–0.67; interaction, P = 0.05), and poorly differentiated tumor (HR 0.16; 95 % CI 0.03–0.85; interaction, P = 0.13). Conclusions Adjuvant gemcitabine chemotherapy for BTC may be effective, particularly for patients with stage III and ICC.