Efficacy and safety of S-1 monotherapy in patients with advanced biliary tract adenocarcinoma: retrospective analysis of 162 patients.

Aim: We investigated the efficacy and safety of S-1 monotherapy for the treatment of advanced biliary tract adenocarcinoma (BTA) in a clinical practice setting.

Methods: We reviewed clinical data from 217 patients with advanced BTA who were treated with S-1 monotherapy between August 2004 and September 2007.

Results: 162 eligible patients were identified. The primary tumors were intrahepatic (n = 57), in the gall bladder (n = 50), in extrahepatic bile ducts (n = 41) and in the ampulla of Vater (n = 14). Sixteen of 120 assessable patients achieved partial responses, with a response rate of 13.3% (95% CI 7.2-19.4%). Another 51 patients had stable disease, with an overall tumor control rate of 55.8% (95% CI 46.9-64.7%). The median time to progression was 2.7 months and the median overall survival time was 6.9 months. Response rates and survival differed significantly according to the primary site of the tumor (p = 0.002 and p < 0.001, respectively), with extrahepatic bile duct adenocarcinoma having the best prognosis. The treatment regimen produced only mild toxicity in most cases (grade 1 or 2), even for patients with hyperbilirubinemia.

Conclusion: S-1 has a favorable toxicity profile and can be safely administered to BTA patients with hyperbilirubinemia. The efficacy of S-1 against advanced BTA depends on the tumor site and is most effective in patients with extrahepatic BTA.