- Patients must have histopathological confirmation of biliary tract carcinoma (BTC) by the Laboratory of Pathology of the NCI prior to entering this study OR histopathological confirmation of carcinoma in the setting of clinical and radiological characteristics which, together with the pathology, are highly suggestive of a diagnosis of biliary tract carcinoma. The term BTC includes intra- or extrahepatic cholangiocarcinoma, gallbladder cancer or ampullary cancer.