Gemcitabine Hydrochloride With or Without Erlotinib Hydrochloride Followed By the Same Chemotherapy Regimen With or Without Radiation Therapy and Capecitabine or Fluorouracil in Treating Patients With Pancreatic Cancer That Has Been Removed By Surgery

Inclusion Criteria:

• Histologically confirmed primary adenocarcinoma of the pancreatic head, neck, or uncinate process

  • Intraductal papillary mucinous neoplasm or invasive adenocarcinoma allowed
  • No non-adenocarcinoma, adenosquamous carcinoma, islet cell (neuroendocrine) tumor, cystadenoma, cystadenocarcinoma, carcinoid tumor, duodenal carcinoma, distal bile duct tumor, or ampullary carcinoma
• Pathologic stage T1-3, N0-1, M0 disease according to American Joint Committee on Cancer (AJCC) 6th edition

• Has undergone a potentially curative resection (i.e., removal of all gross tumor) involving a classic (Whipple) or a pylorus preserving pancreaticoduodenectomy within the past 21-56 days

  • Operative report must contain a statement from the surgeon explicitly detailing that a total gross excision of the primary tumor was achieved
  • Pathology report must include documentation of margin status, size of the tumor, and status of the 3 major surgical margins (bile duct, pancreatic parenchyma, and retroperitoneal [uncinate])
• Post-resection serum CA19-9 =< 180 IU/L
• Tumor tissue block and peripheral blood samples must be submitted to the study's central tumor bank for correlative studies
• No recurrent pancreatic cancer
• Zubrod performance status 0-1
• ANC >= 1,500/mm^3
• Platelet count >= 100,000/mm^3
• Hemoglobin >= 8.0 g/dL (transfusion or other intervention allowed)
• Serum total bilirubin =< 2 times upper limit of normal (ULN)
• Creatinine =< 2 times ULN
• SGOT =< 2.5 times ULN
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• Suitable to receive study radiotherapy, as documented by a radiation oncologist
• Active HIV infection allowed provided the CD4 count is >= 499/mm^3 and the viral load is =< 50 copies/mL
• Total oral caloric intake >= 1,500 calories/day
• No significant nausea and vomiting

• None of the following severe active comorbidities that would preclude study therapy:

  • Unstable angina and/or congestive heart failure requiring hospitalization within the past 6 months
  • Transmural myocardial infarction within the past 3 months
  • Acute bacterial or fungal infection requiring IV antibiotics
  • Chronic obstructive pulmonary disease exacerbation or other respiratory illness requiring hospitalization or precluding study therapy
• No other invasive malignancies within the past 2 years except for nonmelanomatous skin cancer or carcinoma in situ
• See Disease Characteristics

• No prior systemic chemotherapy for pancreatic cancer

  • Prior chemotherapy for a different cancer allowed
• No prior total pancreatectomy, distal pancreatectomy, or central pancreatectomy
• No prior radiotherapy to the region of the study cancer that would result in overlap of radiotherapy fields
• Concurrent highly active antiretroviral treatment (HAART) allowed