DISEASE CHARACTERISTICS: Histologically or cytologically confirmed adenocarcinoma of the pancreas Inoperable locally advanced or metastatic disease Previously untreated disease At least 1 measurable lesion Lesions in a previously irradiated field are not considered measurable Brain metastases allowed provided symptoms are stable and patient is receiving a stable dose of steroids within 1 month prior to study

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: WHO 0-1 Life expectancy: Not specified Hematopoietic: Neutrophil count at least 1,500/mm3 Platelet count at least 100,000/mm3 Hemoglobin at least 9 g/dL Hepatic: Bilirubin no greater than 2 times upper limit of normal (ULN) Alkaline phosphatase no greater than 2 times ULN ALT or AST no greater than 2 times ULN (5 times ULN if liver metastases present) Renal: Creatinine no greater than 1.5 mg/dL OR Creatinine clearance at least 40 mL/min Cardiovascular: No congestive heart failure No angina pectoris (even if medically controlled) No myocardial infarction within the past year No uncontrolled hypertension No arrhythmia Neurologic: No significant neurological disorder except that caused by metastatic disease or psychiatric disorders No clinically significant abnormal findings on audiogram or neurological examination Other: No other serious illness or medical condition No uncontrolled concurrent infection No prior disposition to diarrhea (e.g., Crohn's disease or ulcerative colitis) No poor nutritional status that would be compromised by severe diarrhea No other prior or concurrent malignancy except: Curatively treated nonmelanoma skin cancer or carcinoma in situ of the cervix OR Other cancer curatively treated by surgery alone that has not recurred for more than 5 years No other condition that would preclude study Not pregnant or nursing Negative pregnancy test Fertile patients must use effective contraception during and for at least 6 months after study

PRIOR CONCURRENT THERAPY: Biologic therapy: No prior immunotherapy No concurrent antitumor immunotherapy Chemotherapy: No prior chemotherapy No other concurrent antitumor chemotherapy Endocrine therapy: See Disease Characteristics No prior endocrine therapy No concurrent antitumor hormonal therapy Radiotherapy: See Disease Characteristics Prior single fraction of radiotherapy for palliation allowed No concurrent radiotherapy except for local palliation to a nontarget lesion Surgery: See Disease Characteristics Prior surgeries allowed At least 4 weeks since prior major thoracic and/or abdominal surgery (2 weeks for biliary drainage procedures) and recovered Other: At least 30 days since prior investigational drugs No other concurrent investigational drugs