Gemcitabine With/Out Capecitabine in Locally Advanced, Unresectable, or Metastatic Biliary Cancer

DISEASE CHARACTERISTICS: * Histologically or cytologically proven adenocarcinoma of the biliary tree (intra- and extra-hepatic biliary ducts or gallbladder) * Locally advanced, unresectable, or metastatic disease * Patients with pathologically confirmed metastatic adenocarcinoma consistent with biliary primary with clinical documentation of gallbladder or biliary tree involvement and no evidence of another primary adenocarcinoma are eligible * Must have evidence of disease but measurable disease is not required * Chest x-ray and/or CT scan of the chest, CT scan or MRI of the abdomen, and other radiological examination to document all disease sites have been done within 28 days prior to randomization * No repeat scan needed if a negative scan was performed within 35 days prior to randomization * Patients who have only one site of disease located inside a previous radiotherapy field are eligible * Lesions within a previous radiotherapy field may be considered measurable if documented ≥ 20% increase in size * If the lesion size increase has not been documented since the completion of radiotherapy, and the lesion is still present (i.e. not CR), the lesion is considered evaluable for this trial * Patients with biliary duct obstruction are eligible provided all of the following criteria are met: * Treatable, clinically relevant obstruction * Obstruction has been relieved by internal endoscopic drainage/stenting, palliative bypass surgery or percutaneous …