Radiotherapy Combined With Oxaliplatin and Fluorouracil Followed By Gemcitabine in Treating Patients With Locally Advanced, Unresectable Pancreatic Cancer

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