A pilot study of S-1-based concurrent chemoradiotherapy in patients with biliary tract cancer

Purpose: S-1 chemotherapy is effective against advanced biliary tract cancer. The purpose was to evaluate the efficacy and safety of S-1-based concurrent chemoradiotherapy in patients with advanced biliary tract cancer. Methods: Patients with pathologically-proven advanced biliary tract cancer were eligible. S-1 was orally administered at a dose of 40 mg/m², twice daily from day 1 to 14 and from day 22 to 35; concurrent radiotherapy of 180-200 cGy per fraction was delivered in 25-28 fractions. After treatment completion, tumor response was evaluated by computed tomography. In the first stage of the optimal two-stage phase II design, 18 patients were required. Results: Twenty patients were enrolled between August 2006 and February 2009. The median age was 62.5 years (range 45-77 years). The median follow-up time was 11.6 months (range 1.9-49.1 months). Fifteen patients (75 %) had extrahepatic cholangiocarcinoma, two patients (10 %) had intrahepatic cholangiocarcinoma, and three patients (15 %) had gallbladder cancer. After treatment, a partial response was achieved in three patients (15 %), and stable disease was achieved in 14 patients (70 %). The overall response rate was 15 %, and the disease stabilization rate was 85 %. There was no grade 4 toxicity or treatment-related death. The common grade 3 toxicities were thrombocytopenia (15 %), neutropenia (10 %), and nausea (10 %). The median progression-free survival and median overall survival were 5.9 months (range 2.2-9.5 months) and 10.8 months (range 1.1-20.4 months), respectively. Conclusions: This study shows that S-1-based concurrent chemoradiotherapy is feasible and tolerable in patients with advanced biliary tract cancer. It will be further confirmed in a following large-scale phase II study.