[Two cases of advanced extrahepatic bile duct cancer successfully treated by S-1 monotherapy].

Biliary tract cancers, including extrahepatic bile duct cancer, are often diagnosed at an advanced stage; however,no standard therapies have been established as yet for this disease,and new,effective chemotherapeutic agents are being sought. Recently, a late phase II study of S-1, an oral fluoropyrimidine, in 40 patients with advanced biliary tract cancer yielded a good response rate of 35.0%. In this article,we report two patients with advanced extrahepatic bile duct cancer enrolled in the study who showed a partial response to S-1 monotherapy.