Radiotherapy plus Single-Agent Chemotherapy/Radiosensitization. Involved-field irradiation using 4-15 MV photons; plus Gemcitabine, NSC-613327.

This is a Phase I trial of gemcitabine given weekly as a 30 minute infusion administered concurrently with radiation in patients with locally advanced or locally recurrent pancreatic carcinoma. Patients will be treated with external beam radiation therapy in a standard manner. Gemcitabine will be administered as a 30 minute infusion beginning on the first day of irradiation and weekly afterwards for a total of 5 doses. Patients will be assessed clinically for acute toxicity which will be graded per RTOG and DCT toxicity grading system.

DISEASE CHARACTERISTICS:

Histologically or cytologically proven unresectable adenocarcinoma of the pancreas or ampulla of Vater. Surgical consult at NCI confirming unresectability fulfills requirement.

Unresectable disease defined as tumor with: Gross involvement of regional nodes or direct extension to any of the following sites: Duodenum, Spleen, Bile duct , Colon, Peripancreatic tissue, Adjacent large vessels, Stomach.

Metastatic disease requiring local radiotherapy allowed. No CNS metastasis.

No lymphomas or neuroendocrine tumors.

No peritoneal carcinomatosis.

PRIOR/CONCURRENT THERAPY:

Biologic Therapy: More than 4 weeks since immunotherapy.

Chemotherapy:

No prior chemotherapy for newly diagnosed disease.

More than 4 weeks since chemotherapy for recurrent disease (6 weeks since nitrosoureas, mitomycin, or suramin).

Endocrine Therapy: More than 4 weeks since hormonal therapy.

Radiotherapy:

No prior radiotherapy for newly diagnosed disease.

No prior abdominal or pelvic radiotherapy.

More than 4 weeks since radiotherapy for recurrent disease. No prior radiotherapy for locally advanced disease after resection allowed.

Surgery:

Prior resection allowed.

Biliary decompression or gastric bypass allowed.

PATIENT CHARACTERISTICS:

Age: 18 and over.

Performance status: ECOG 0-2.

Hematopoietic:

ANC greater than 2,000/mm(3).

Platelets greater than 100,000/mm(3).

Hepatic: AST/ALT no greater than 2.5 times normal.

Renal:

Creatinine less than 1.5 mg/dL.

Creatinine clearance at least 60 mL/min,

Cardiovascular:

No myocardial infarction within 6 months.

No unstable angina.

No congestive heart failure (NYHA class III/IV).

OTHER:

HIV seronegative.

No medical or psychiatric contraindication to protocol therapy.

No concurrent malignancy other than: Skin cancer, Cervical carcinoma in situ.

No pregnant or nursing women.

Adequate contraception required of fertile patients.