Feasibility study of postoperative adjuvant chemotherapy with S-1 in patients with biliary tract cancer

The role of adjuvant chemotherapy has not yet been established for patients with resected biliary tract cancer. S-1 has been shown to exert activity against advanced biliary tract cancer. Therefore, we evaluated the feasibility of adjuvant chemotherapy with S-1 in patients with resected biliary tract cancer. Patients with complete macroscopic resection of intrahepatic/extrahepatic bile duct, gall bladder, or ampullary cancer were eligible. S-1 was administered orally twice daily for 4 weeks every 6 weeks, up to 4 cycles. The treatment was continued up to 24 weeks or until recurrence/appearance of unacceptable toxicity. The primary endpoint was the treatment completion rate, which was defined as the percentage of patients who received a relative dose intensity of ae<yen> 75%. This trial was registered as UMIN000004051. Thirty-three patients were enrolled between June 2010 and March 2011. The relative dose intensity was ae<yen> 75% in 27 patients representing a treatment completion rate of 81.8%. The most common grade 3/4 adverse event was neutropenia (18%). Grade 2 nausea or diarrhea was observed in 12%. The 3-year relapse-free survival rate was 39.4%. The 3-year survival rate was 54.5%. Adjuvant chemotherapy with S-1 is feasible treatment in patients with resected biliary tract cancer. It is necessary to conduct a phase III study to confirm the efficacy of adjuvant therapy of S-1 in patients with resected BTC.