Gemcitabine, Capecitabine, and Bevacizumab in Treating Patients With Metastatic or Unresectable Pancreatic Cancer

DISEASE CHARACTERISTICS: * Histologically confirmed adenocarcinoma of the pancreas meeting 1 of the following criteria: * Newly diagnosed or previously treated metastatic disease * Unresectable disease * No CNS or brain metastases PATIENT CHARACTERISTICS: Age * Over 18 Performance status * ECOG 0-1 Life expectancy * More than 3 months Hematopoietic * Absolute neutrophil count \> 1,500/mm\^3 * WBC \> 3,000/mm\^3 * Platelet count \> 100,000/mm\^3 * Hemoglobin ≥ 9 g/dL (transfusion or epoetin alfa allowed) * No evidence of bleeding diathesis or coagulopathy Hepatic * Bilirubin \< 2 mg/dL * AST or ALT \< 2.5 times upper limit of normal (ULN) (5 times ULN if liver metastases are present) * INR \< 1.5 (except for patients receiving full-dose warfarin) Renal * Creatinine \< 1.5 mg/dL * No proteinuria OR * Urine protein \< 500 mg by 24-hour urine collection * No clinically significant impairment of renal function Cardiovascular * No uncontrolled hypertension (blood pressure \> 160/110 mm Hg on medication) * No New York Heart Association class II-IV congestive heart failure * No unstable symptomatic arrhythmia requiring medication * Chronic atrial arrhythmia (i.e., atrial fibrillation or paroxysmal supraventricular tachycardia) allowed * No clinically significant grade II-IV peripheral vascular disease * No arterial thromboembolic event within the past 6 months, including any of the following: * Transient ischemic attack * Cerebrovascular accident * Unstable angina * Myocardial infarction Other * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception * No other serious systemic disease * No significant traumatic injury within the past 28 days * No serious non-healing wound, ulcer, or bone fracture * No history of other disease, metabolic dysfunction, physical examination finding, or clinical laboratory finding that would preclude study participation PRIOR CONCURRENT THERAPY: Biologic therapy * Not specified Chemotherapy * Not specified Endocrine therapy * Not specified Radiotherapy * Not specified Surgery * More than 28 days since prior major surgery or open biopsy * More than 7 days since prior fine needle aspirations or core biopsies * No concurrent major surgery Other * More than 4 weeks since prior and no concurrent participation in any other experimental drug study * More than 12 months since prior adjuvant therapy * No prior systemic therapy for metastatic disease