A Pilot Study to Evaluate Radiotherapy-Induced Anti-Tumor Immunity in Metastatic Carcinoma of the Pancreas

Inclusion Criteria: * Histological or cytological diagnosis of pancreatic carcinoma * Patients ≥ 18 years of age * Eastern Cooperative Oncology Group (ECOG) performance status 0,1,or 2 * Patients must have distant metastatic disease (stage 4) * Satisfactory organ and bone marrow function as defined by: Absolute neutrophil count\> 1,000/uL, Platelets \> 75,000uL Hemoglobin \> 9 Bilirubin ≤ 2.0x the institutional normal upper limit unless secondary to bile duct obstruction by tumor, * Creatinine ≤ 1.5x the institutional normal upper limit * Serum alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤ 5x the institutional normal upper limit. * A clinical recommendation for radiotherapy to the primary or a metastatic lesion had been made. * Must be able to provide informed consent. Exclusion Criteria: * No prior radiation to the area planned for radiotherapy * Active invasive cancer other than pancreatic adenocarcinoma. Non-melanoma skin cancer, superficial cervical or bladder cancer and prostate cancer with PSA level \< 1.0 are not excluded. * Known HIV, HCV and/or HBV positive (by patient report/medical record) * Patients with ongoing or active infection * Planned concurrent treatment with systemic high dose corticosteroids. * Received an anticancer treatment (systemic therapy or radiation therapy)within 21 days prior to enrollment. * Immunotherapy (e.g. monoclonal antibodies)within 21 days prior to enrollment. * Immunosuppressive therapies (e.g. steroids, cyclosporine) are not permitted.