DISEASE CHARACTERISTICS: Histologically or cytologically confirmed ductal carcinoma of the exocrine pancreas Locally advanced or metastatic Failed 1, but no more than 1, prior gemcitabine-containing chemotherapy regimen (either as a single agent or in combination with another agent) (See criteria for prior radiation using gemcitabine or fluorouracil at diminished doses in Prior/Concurrent Therapy section) No neuroendocrine or islet cell tumors or lymphoma of the pancreas

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: Karnofsky 70-100% Life expectancy: Not specified Hematopoietic: WBC at least 3,000/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Absolute neutrophil count at least 1,500/mm3 Hepatic: Bilirubin no greater than 2.0 mg/dL AST or ALT no greater than 5.0 times upper limit of normal (ULN) Alkaline phosphatase no greater than 5.0 times ULN Renal: Creatinine no greater than 1.5 mg/dL Cardiovascular: No clinically significant active heart disease Other: Fertile patients must use effective contraception No history of retinopathy or macular degeneration No other malignancy within the past 5 years except basal cell or squamous cell skin cancer or carcinoma in situ of the cervix No other significant medical and/or psychiatric condition that would preclude study

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior biologic therapy No concurrent biologic therapy Chemotherapy: See Disease Characteristics At least 21 days since prior chemotherapy and recovered No prior systemic treatment with fluorouracil, fluorouracil-uracil, raltitrexed, or capecitabine in combination with gemcitabine Prior fluorouracil or gemcitabine allowed as radiosensitizing agents when given 2 weeks before, during, or 2 weeks after radiotherapy No prior cumulative mitomycin dose greater than 25 mg/m2 Endocrine therapy: Not specified Radiotherapy: At least 21 days since prior radiotherapy and recovered Surgery: No prior surgery No concurrent surgery Other: At least 21 days since prior participation in other investigational study