This phase II trial is studying how well giving radiation therapy together with oxaliplatin and fluorouracil followed by gemcitabine works in treating patients with locally advanced, unresectable pancreatic cancer. Radiation therapy uses high-energy x-rays to damage tumor cells. Drugs used in chemotherapy, such as oxaliplatin, fluorouracil, and gemcitabine, work in different ways to stop tumor cells from dividing so they stop growing or die. Oxaliplatin may also make the tumor cells more sensitive to radiation therapy. Giving radiation therapy with chemotherapy may kill more tumor cells.

PRIMARY OBJECTIVES:

I. Determine the 1-year survival rate in patients with locally advanced, unresectable adenocarcinoma of the pancreas treated with concurrent external beam radiotherapy, oxaliplatin, and fluorouracil followed by gemcitabine.

SECONDARY OBJECTIVES:

I. Determine overall survival, time to disease progression, and confirmed response rate in patients treated with this regimen.

II. Determine toxicity of this regimen in these patients.

OUTLINE: This is a multicenter study.

Patients undergo radiotherapy once daily, 5 days a week, for 5.5 weeks. Beginning concurrently with radiotherapy, patients receive oxaliplatin IV over 2 hours on days 1, 15, and 29 and fluorouracil IV continuously for 5.5 weeks. Beginning 4-6 weeks after the completion of chemoradiotherapy, patients receive gemcitabine IV over 30 minutes on days 1 and 8. Treatment with gemcitabine repeats every 21 days for 4 courses in the absence of disease progression or unacceptable toxicity.

Patients are followed every 3 months for 2 years and then every 6 months for 1 year.

Inclusion Criteria:

• Histologically or cytologically confirmed adenocarcinoma of the pancreas

  • Unresectable disease, including subtotal resection and gross residual disease
  • Locally advanced disease

• No cystadenocarcinoma of the pancreas

• No pancreatic tumors of neuroendocrine origin

• No microscopic residual disease as only evidence of pancreatic cancer

• All disease must be encompassable within standard radiotherapy fields for pancreatic cancer

• No distant metastases (liver or lung metastases or peritoneal spread)

  • No evidence of metastatic disease outside the planned radiotherapy field

• Performance status - ECOG 0-1

• Absolute neutrophil count ≥ 1,500/mm^3

• Platelet count ≥ 100,000/mm^3

• Hemoglobin ≥ 9.0 g/dL

• Bilirubin ≤ 2 times upper limit of normal (ULN)

• AST ≤ 3 times ULN

• Creatinine ≤ 1.5 times ULN

• Not pregnant or nursing

• Negative pregnancy test

• Fertile patients must use effective contraception

• Able to maintain adequate oral nutrition

• No significant infection

• No significant nausea or vomiting

• No other medical condition that would preclude study participation

• No other malignancy within the past 3 years except nonmelanoma skin cancer, carcinoma in situ of the cervix, or organ-confined prostate cancer (Gleason score < 7)

• No known allergy to platinum compounds

• No prior biologic therapy

• No concurrent biologic therapy

• No concurrent immunotherapy

• No prior chemotherapy

• No other concurrent chemotherapy

• No prior radiotherapy that would overlap planned radiotherapy fields

• No other concurrent radiotherapy

• See Disease Characteristics

• At least 21 days since prior laparotomy