Gemcitabine Hydrochloride in Treating Patients With Pancreatic Cancer That Has Been Removed by Surgery

DISEASE CHARACTERISTICS: * Histologically confirmed adenocarcinoma of the pancreas * No metastatic or locally advanced (nonresectable) disease * Must have undergone curative surgical resection * Must have macroscopically complete (R0 or R1) surgical outcome * Adjuvant treatment with gemcitabine hydrochloride (for 6 months) is necessary, and able to start treatment within 8 weeks of surgical resection * No ampullomas or endocrine carcinomas PATIENT CHARACTERISTICS: * WHO performance status 0-2 * Neutrophil count ≥ 1,500/mm³ * Platelet count ≥ 100,000/mm³ * Alkaline phosphatases ≤ 5 times upper limit of normal * Total bilirubin ≤ 50 µmol/L * Creatinine clearance ≥ 60 mL/min * Not pregnant or nursing * Able to start adjuvant chemotherapy within 8 weeks of surgery * No evolving infectious syndrome (fever \> 38°C or abscess) * No contraindication for gemcitabine hydrochloride * No prior malignant tumor except for cutaneous basocellular carcinoma or in situ cervical epithelioma (prior history of malignant tumor diagnosed and treated more than 10 years ago allowed, except for breast cancer and melanoma) PRIOR CONCURRENT THERAPY: * See Disease Characteristics * No chemotherapy or radiotherapy within the past 10 years * No prior ablation surgery leaving macroscopic tumor residues (R2)