Inclusion Criteria

DISEASE CHARACTERISTICS:

- Histologically or cytologically confirmed biliary tract cancer

- Locally advanced, unresectable, or metastatic disease

- Metastatic adenocarcinoma with clinical documentation of gallbladder or bile tree
involvement with no evidence of another primary adenocarcinoma allowed

- Measurable or nonmeasurable disease

- Treatable biliary duct obstruction must be relieved by either internal endoscopic
drainage/stenting or palliative bypass surgery before study entry

- Symptomatic biliary tract cancer and has at least 1 of the following:

- Karnofsky 60-80%

- Baseline analgesic consumption at least 10 mg of morphine equivalents per day

- Baseline pain intensity score of at least 20 mm out of a possible 100 mm

- No prior or concurrent CNS metastasis

PATIENT CHARACTERISTICS:

Age

- 18 to 80

Performance status

- See Disease Characteristics

- Karnofsky 60-100%

Life expectancy

- Not specified

Hematopoietic

- Neutrophil count at least 1,500/mm^3

- Platelet count at least 100,000/mm^3

- Hemoglobin at least 10.0 g/dL

Hepatic

- Bilirubin no greater than 4 times upper limit of normal (ULN)

- Alkaline phosphatase no greater than 5 times ULN

- AST and ALT no greater than 5 times ULN

Renal

- Creatinine clearance greater than 50 mL/min

Cardiovascular

- No uncontrolled cardiovascular disease

Gastrointestinal

- Able to ingest oral medication

- No malabsorption syndrome

- No intractable nausea and/or vomiting

- No partial small bowel obstruction

Other

- Not pregnant or nursing

- Negative pregnancy test

- Fertile patients must use effective contraception during and for 1 year after study
participation

- No active autoimmune disease

- No uncontrolled diabetes

- No known hypersensitivity to fluorouracil

- No known dihydropyrimidine dehydrogenase deficiency

- No definitive contraindication to corticosteroids

- No prior significant neurologic or psychiatric disorders (e.g., psychotic disorders,
dementia, or seizures) that would preclude understanding or providing informed
consent

- No prior severe reaction to fluoropyrimidine therapy

- No psychiatric disorder, cognitive dysfunction, or language problem that would
preclude filling out the quality of life questionnaire or patient diary

- No other serious underlying medical condition that would preclude study participation

- No other malignancy within the past 5 years except nonmelanoma skin cancer or
adequately treated carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy

- No prior biologic therapy

- No prior immunotherapy

Chemotherapy

- No prior chemotherapy for advanced/metastatic disease

- No prior palliative chemotherapy

Endocrine therapy

- No concurrent megestrol

Radiotherapy

- More than 4 weeks since prior radiotherapy

- No concurrent radiotherapy

- Treatment of a single painful lesion allowed

Surgery

- See Disease Characteristics

- Prior Whipple procedure allowed

- Prior duodenal bypass allowed

- No concurrent endoscopic or external biliary drainage as a consequence of progressive
malignant bile duct obstruction

- Drainage as a consequence of nonmalignant bile duct obstruction allowed

Other

- More than 30 days since prior treatment within a clinical study

- No other concurrent anticancer drugs

- No other concurrent investigational drugs

- No concurrent sorivudine or its chemically-related analogues (e.g., lamivudine)