OBJECTIVES: I. Determine the maximum tolerated dose of gemcitabine in combination with radiation therapy to patients with locally advanced and/or unresectable adenocarcinoma of the pancreas. II. Determine the dose limiting toxic effects of this combination therapy in these patients. III. Evaluate the ability of these patients to tolerate induction and then maintenance therapy with gemcitabine preceding and following combination therapy. IV. Evaluate the efficacy (response rate, pattern of failure, and survival) of this combination therapy in these patients.

OUTLINE: This is a dose escalation study of gemcitabine. Part I: Patients receive gemcitabine as a continuous infusion over 30 minutes once weekly for 3 weeks followed by 1 week of rest. Part II: Gemcitabine IV is administered as a 30 minute infusion twice a week (Monday and Thursday) for 5-6 weeks. Patients receive radiation therapy 5 days a week for 5-6 weeks. In the absence of dose-limiting toxicity (DLT) in the first 6 patients treated, subsequent cohorts of 6 patients each receive escalating doses of gemcitabine on the same schedule. If DLT occurs in 2 of 6 patients at a given dose level, then dose escalation ceases and the next lower dose is declared the maximum tolerated dose. Part III: In the absence of toxicity and disease progression, patients continue gemcitabine for 3 additional courses. Maintenance gemcitabine starts 4 weeks after the completion of radiation therapy and is administered once weekly for 3 weeks followed by 1 week of rest. Patients are followed until death.

PROJECTED ACCRUAL: This study will accrue 15-30 patients in approximately 24 months.