Panitumumab, Chemotherapy, and External-Beam Radiation Therapy in Treating Patients With Locally Advanced Pancreatic Cancer That Cannot be Removed by Surgery

DISEASE CHARACTERISTICS: * Histologically or cytologically confirmed unresectable adenocarcinoma of the pancreas * Including subtotal resection and gross residual disease * No microscopic residual disease only * Measurable disease is not required * Disease is encompassable within standard radiotherapy fields for pancreatic cancer * No evidence of metastatic disease outside of the planned radiotherapy field * No cystadenocarcinoma of the pancreas or pancreatic tumors of neuroendocrine origin * No distant metastases (i.e., liver or lung metastases or peritoneal spread) * No history or known presence of CNS metastases PATIENT CHARACTERISTICS: * Eastern Cooperative Oncology Group (ECOG) performance status 0-1 * ANC ≥ 1,500/mm³ * Hemoglobin ≥ 9.0 g/dL * Platelet count ≥ 100,000/mm³ * Total bilirubin ≤ 3 times upper limit of normal (ULN)\* NOTE: \*Biliary stent placement or surgical bypass should be considered prior to treatment if impending bile duct obstruction by tumor * AST ≤ 3 times ULN * Creatinine ≤ 2.0 times ULN * Magnesium normal * Willing to return to an North Central Cancer Treatment Group (NCCTG) institution for follow-up * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception during and for at least 6 months after treatment with panitumumab * No prior or concurrent malignancy unless disease-free ≥ 3 years except for non-melanoma skin cancer, carcinoma in situ of the cervix, or organ confined prostate cancer with Gleason score \< 7 * No nausea or vomiting \> grade 1 * No uncontrolled intercurrent illness including, but not limited to, any the following: * Ongoing or active infection * Psychiatric illness or social situations that would limit compliance with study requirements * No New York Heart Association clinically significant cardiovascular disease ≥ grade 2, including any of the following within the past year: * Myocardial infarction * Unstable angina * Symptomatic congestive heart failure * Serious, uncontrolled cardiac arrhythmia * No known HIV positivity * No known hepatitis C virus or acute or chronic active hepatitis B infection * Adequate oral nutrition PRIOR CONCURRENT THERAPY: * More than 21 days since prior laparotomy * No prior anti-epidermal growth factor receptor (EGFR) antibody therapy (e.g., cetuximab) * No prior small molecule EGFR inhibitors (e.g., gefitinib, erlotinib, or lapatinib) * No prior radiotherapy that would overlap with planned radiotherapy fields * No prior or other concurrent chemotherapy * No prior or other concurrent biologic therapy * More than 4 weeks since prior and no concurrent or planned participation in another experimental drug study except studies with specific interventions intended to treat rashes associated with EGFR agents (e.g., N05C4) * No concurrent enteral hyperalimentation * No concurrent chronic immunosuppressive agents (e.g., methotrexate, cyclosporine, or corticosteroids) * No concurrent colony-stimulating factors during the first course of therapy * No other concurrent immunotherapy or radiotherapy