Vaccine Therapy With or Without Cyclophosphamide in Treating Patients Undergoing Chemotherapy and Radiation Therapy for Stage I or Stage II Pancreatic Cancer That Can Be Removed by Surgery

OBJECTIVES: Primary * To evaluate the safety and feasibility of a GVAX pancreatic cancer vaccine (GM-CSF gene-transfected allogeneic pancreatic cancer vaccine) when administered alone or in combination with a single intravenous dose or daily metronomic oral doses of cyclophosphamide as neoadjuvant and adjuvant treatment in patients with resectable stage I or II adenocarcinoma of the head, neck, or uncinate process of the pancreas. * To assess the immune cell infiltrates, particularly T-regulatory cells (Tregs) and CD4+ and CD8+ effector T cells, after neoadjuvant GVAX pancreatic cancer vaccination. * To assess the changes in the number and function of peripheral mesothelin-specific CD8+ T cells and CD4+, FoxP3+, and GITR+ Tregs after each GVAX pancreatic cancer vaccination when administered alone or in combination with a single dose or metronomic doses of cyclophosphamide. Secondary * To estimate disease-free and overall survival of patients treated with these regimens. * To estimate the effect of immune parameters on disease-free and overall survival of these patients. OUTLINE: Patients are randomized to 1 of 3 treatment arms. * Arm A: Patients receive GVAX pancreatic cancer vaccine intradermally (ID) on day 1 and undergo pancreaticoduodenectomy on day 15. Approximately 6-10 weeks after surgery, patients receive an additional dose of the vaccine. Beginning approximately 1 month after vaccination, patients receive standard adjuvant chemoradiotherapy comprising gemcitabine, fluorouracil or capecitabine, and radiotherapy over 26-28 weeks. Beginning approximately 4-8 weeks after the completion of chemoradiotherapy, patients receive the vaccine on day 1. Treatment with the vaccine repeats every 28 days for 4 courses. * Arm B: Patients receive low-dose cyclophosphamide IV on day 0 and GVAX pancreatic cancer vaccine ID on day 1. Patients undergo pancreaticoduodenectomy on day 15. Approximately 6-10 weeks after surgery, patients receive low-dose cyclophosphamide IV on day 0 and the vaccine on day 1. Beginning approximately 1 month after vaccination, patients receive standard adjuvant chemoradiotherapy comprising gemcitabine, fluorouracil or capecitabine, and radiotherapy over 26-28 weeks. Beginning approximately 4-8 weeks after the completion of chemoradiotherapy, patients receive low-dose cyclophosphamide IV on day 0 and the vaccine on day 1. Treatment with cyclophosphamide and the vaccine repeats every 28 days for 4 courses. * Arm C: Patients receive GVAX pancreatic cancer vaccine ID on day 1 and low-dose oral cyclophosphamide twice daily on days 1-7. Patients undergo pancreaticoduodenectomy on day 15. Approximately 6-10 weeks after surgery, patients receive the vaccine on day 1 and low-dose oral cyclophosphamide twice daily on days 1-7 and 15-21. Beginning approximately 1 month after vaccination, patients receive standard adjuvant chemoradiotherapy comprising gemcitabine, fluorouracil or capecitabine, and radiotherapy over 26-28 weeks. Beginning approximately 4-8 weeks after the completion of chemoradiotherapy, patients receive the vaccine on day 1 and low-dose oral cyclophosphamide twice daily on days 1-7 and 15-21. Treatment with the vaccine and cyclophosphamide repeats every 28 days for 4 courses. Patients undergo blood sample collection periodically for correlative laboratory studies, including immune cell analysis. Immune cell analysis includes monitoring the quantitative change of peripheral blood lymphocytes, including regulatory T cells (Tregs), and functional analysis of T-cell immune response. Tumor tissue samples collected at the time of surgery are analyzed for tumor antigens and infiltrating immune cells by immunohistochemistry and quantitative real-time PCR. After completion of study treatment, patients are followed periodically.