RATIONALE: Drugs used in chemotherapy use different ways to stop tumor cells from dividing so they stop growing or die. Combining more than one drug may kill more tumor cells. Chemotherapy following surgery may be an effective treatment for pancreatic cancer.

PURPOSE: Phase II trial to study the effectiveness of combination chemotherapy in treating patients with stage II or stage III pancreatic cancer that has not been surgically removed.

OBJECTIVES: I. Assess the one year overall survival rate of patients with advanced, unresectable pancreatic cancer treated with fluorouracil, leucovorin, mitomycin and dipyridamole. II. Assess the response rate in this group of patients. III. Evaluate the frequency and severity of the toxic effects associated with this therapy. IV. Assess the rate of resectability in patients who respond to therapy.

OUTLINE: All patients undergo surgical placement of an indwelling central venous line. Patients receive fluorouracil IV by continuous infusion on days 1-28, leucovorin calcium IV on days 1, 8, 15, and 22, oral dipyridamole on days 1-28, and mitomycin IV every 6 weeks starting on day 1. Treatment repeats every 6 weeks for 4 courses. Patients with a partial or complete response are reevaluated for possible surgical resection. Resected patients resume chemotherapy 4-8 weeks after surgery for an additional 16 weeks. Patients are followed every 6 months for 2 years, then annually until death.

PROJECTED ACCRUAL: A total of 55 patients will be accrued for this study.

DISEASE CHARACTERISTICS: Histologically or cytologically proven stage II or III pancreatic adenocarcinoma Ductal adenocarcinoma Mucinous noncystic carcinoma Signet ring cell carcinoma Adenosquamous carcinoma Undifferentiated (anaplastic) carcinoma Mixed ductal-endocrine carcinoma Well differentiated adenocarcinoma Moderately well or poorly differentiated adenocarcinoma Undifferentiated ductal carcinoma Must have unresectable and localized disease Measurable or evaluable disease

PATIENT CHARACTERISTICS: Age: Not specified Performance status: SWOG 0-2 Life expectancy: Not specified Hematopoietic: Not specified Hepatic: Not specified Renal: Not specified Other: Not pregnant or nursing Fertile patients must use effective contraception Loss of no greater than 15% of actual body weight Oral intake of greater than 1,200 calories per day No other malignancy within the past 5 years except adequately treated basal or squamous cell skin cancer, carcinoma in situ of the cervix, or any stage I or II cancer that is currently in complete remission

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior systemic chemotherapy for pancreatic cancer Endocrine therapy: Not specified Radiotherapy: No prior radiation therapy for pancreatic cancer Surgery: At least 2 weeks since prior surgical bypass procedure and recovered