Bevacizumab and Capecitabine as First-Line Therapy in Treating Older Patients With Metastatic Colorectal Cancer

DISEASE CHARACTERISTICS: * Histologically\* or cytologically\* confirmed colorectal cancer * Site of primary tumor must have been confirmed by endoscopy, radiography, or surgery * Metastatic disease NOTE: \*Patients with a history of surgically treated colorectal cancer who subsequently develop recurrent metastatic disease do not require histologic or cytologic confirmation of metastatic disease unless an interval of \> 5 years has elapsed between initial primary surgery and the development of metastases * Measurable disease * At least 1 unidimensionally measurable lesion ≥ 20 mm by conventional techniques OR ≥ 10 mm by spiral CT scan * No known curative therapy exists * No history or evidence of CNS disease by physical exam (e.g., primary brain tumor or brain or CNS metastases) PATIENT CHARACTERISTICS: Age * 70 and over Performance status * ECOG 0-1 Life expectancy * More than 3 months Hematopoietic * Absolute neutrophil count ≥ 1,500/mm\^3 * Platelet count ≥ 100,000/mm\^3 * Hemoglobin ≥ 9 g/dL * No bleeding diathesis or coagulopathy Hepatic * Bilirubin normal * AST and ALT ≤ 3 times upper limit of normal (ULN) * INR \< 1.5 (unless on therapeutic anticoagulants) * No unstable or uncompensated hepatic disease Renal * Creatinine \< 1.2 times ULN OR * Creatinine clearance \> 60 mL/min * No unstable or uncompensated renal disease Cardiovascular * No history of stroke * No uncontrolled hypertension (i.e., blood pressure \> 150/100 mm Hg on medication) * No myocardial infarction within the past year * No New York Heart Association class II-IV congestive heart failure * No unstable angina * No serious cardiac dysrhythmia requiring medication * No other clinically significant cardiovascular disease * No other unstable or uncompensated cardiac disease Pulmonary * No unstable or uncompensated respiratory disease Other * Fertile patients must use effective contraception * Able to receive oral medication * No known hypersensitivity to fluorouracil or capecitabine * No known dihydropyrimidine dehydrogenase deficiency * No seizures not controlled by standard medical therapy * No serious nonhealing wound, ulcer, or bone fracture * No other malignancy within the past 5 years except completely excised nonmelanoma skin cancer (with no evidence of recurrent disease) or carcinoma in situ of the cervix * No other severe or uncontrolled systemic disease PRIOR CONCURRENT THERAPY: Biologic therapy * No prior bevacizumab Chemotherapy * Prior adjuvant fluorouracil and leucovorin calcium allowed provided the last treatment was administered \> 6 months before the development of metastatic disease * No prior chemotherapy for metastatic colon cancer * No prior irinotecan or oxaliplatin Endocrine therapy * Not specified Radiotherapy * Not specified Surgery * See Disease Characteristics * More than 28 days since prior and no concurrent major surgery * More than 28 days since prior open biopsy * More than 7 days since prior fine needle aspiration or core biopsy Other * More than 4 weeks since prior and no concurrent participation in another experimental drug study * More than 30 days since prior non-approved or investigational drugs