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

RATIONALE: Vaccines made from gene-modified tumor cells may help the body build an effective immune response to kill pancreatic cancer cells. Drugs used in chemotherapy, such as cyclophosphamide, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving vaccine therapy together with cyclophosphamide may kill more tumor cells. It is not yet known whether vaccine therapy is more effective with or without cyclophosphamide in treating patients with pancreatic cancer. PURPOSE: This randomized clinical trial is studying the side effects of vaccine therapy and to see how well it works when given 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.