Randomized Phase II Study of Gemcitabine Versus S-1 Adjuvant Therapy After Hemihepatectomy for Biliary Tract Cancer

There is no standard adjuvant therapy after liver hemi-hepatectomy due to bile duct cancer, because of high surgical morbidity ratio and high adverse event ratio of adjuvant therapy. For example, our preliminary results showed that regular gemcitabine administration (1000mg/m2, day 1, 8, 15 every 4 weeks) after hemihepatectomy was too toxic and induced severe leukocytopenia and/or thrombocytopenia. Formerly, the investigators planned the study to decide more safety adjuvant protocol (recommend dose: RD) for Gemcitabine or S-1 after hemihepatectomy using Continuous Reassessment Method (CRM) analysis and decided the recommend doses. Note: In the former study, the investigators decided that tolerable ratio of Dose Limiting Toxicity (DLT) would be less than 10%. Herein, the investigators planned the study to evaluate efficacy (recurrent free survival as primary outcome, and overall-survival as secondary outcome) and safety (as secondary outcome) in our recommended protocols, and to compare the efficacy as randomized control trial.