Gemcitabine and Erlotinib Before and After Surgery in Treating Patients With Pancreatic Cancer That Can Be Removed by Surgery

Eligibility Criteria: 1. Cytologic or histologic proof of adenocarcinoma of the pancreatic head or uncinate process. NOTE: Patients with tumors of the pancreatic neck, body or tail are not eligible. Patients with evidence of neuroendocrine tumors, duodenal adenocarcinoma, or ampullary adenocarcinoma are not eligible. 2. Localized, potentially resectable tumors as defined below. All patients must be staged with a chest X-ray or CT, and abdominal CT (contrast-enhanced, helical thin-cut) or MRI. Radiological resectability is defined by the following criteria on abdominal imaging: * No evidence of tumor extension to the celiac axis, hepatic artery, or superior mesenteric artery * No evidence of tumor encasement or occlusion of the superior mesenteric vein (SMV) or the SMV/portal vein confluence * No evidence of visceral or peritoneal metastases NOTE: Patients with borderline resectable or marginally resectable pancreatic cancer are not eligible. Patients must meet all objective imaging criteria outlined above. 3. ≥ 18 years of age 4. ECOG/Zubrod performance status of 0 or 1 5. Baseline weight loss ≤ 15% of premorbid weight 6. Patient must have adequate hematologic, renal, and hepatic function as defined by: * WBC ≥ 2,000 cells/mm³ * ANC ≥ 1,500 cells/mm³ * Platelets ≥ 100,000 cells/mm³ * Serum bilirubin ≤ 2.5 mg/dL * Serum creatinine ≤ 1.5 mg/dL or a calculated creatinine clearance of ≥ 50 ml/min (24 hour urine collection) * ALT \< 2.5 times …