RATIONALE: Drugs used in chemotherapy, such as gemcitabine, work in different ways to stop tumor cells from dividing so they stop growing or die. Monoclonal antibodies, such as cetuximab, can locate tumor cells and either kill them or deliver tumor-killing substances to them without harming normal cells. It is not yet known whether gemcitabine is more effective with or without cetuximab in treating pancreatic cancer.