DISEASE CHARACTERISTICS:

• Histologically confirmed colorectal cancer

  • Unresectable metastatic disease
• Measurable disease, defined as ≥ 1 measurable lesion according to RECIST criteria
• No prior chemotherapy for metastatic disease
• No untreated brain metastases, spinal cord compression, or primary brain tumors
• No history or evidence of CNS disease by physical examination unless adequately treated (e.g., uncontrolled seizure despite standard medical therapy or history of stroke)

PATIENT CHARACTERISTICS:

Inclusion criteria:

• ECOG performance status (PS) 0-2 (≤ 70 years of age) OR ECOG PS 0 (71-75 years of age)
• Life expectancy ≥ 12 weeks
• Neutrophils ≥ 1.5 x 10^9/L
• Platelet count ≥ 100 x 10^9/L
• Hemoglobin > 9 g/dL
• Total bilirubin ≤ 1.5 times upper limit of normal (ULN)
• AST and ALT ≤ 2.5 times ULN (≤ 5 times ULN if f liver metastases present)
• Alkaline phosphatase ≤ 2.5 times ULN (≤ 5 times ULN if liver metastases present)
• Creatinine clearance > 50 mL/min OR serum creatinine ≤ 1.5 times ULN
• Proteinuria < 2+ by dipstick OR urine protein ≤ 1 g by 24-hr urine collection
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception

Exclusion criteria:

• Serious, nonhealing wound, ulcer, or bone fracture
• Evidence of bleeding diathesis or coagulopathy
• Uncontrolled hypertension

• Clinically significant (i.e., active) cardiovascular disease, including any of the following:

  • Cerebrovascular accidents within the past 6 months
  • Myocardial infarction within the past 6 months
  • Unstable angina
  • New York Heart Association class II-IV congestive heart failure
  • Serious cardiac arrhythmia requiring medication
• Known allergy to Chinese hamster ovary cell proteins or any of the components of the study medications
• Other co-existing malignancy or malignancy diagnosed within the past 5 years, except for basal cell or squamous cell carcinoma, or carcinoma in situ of the cervix
• Symptomatic peripheral neuropathy ≥ grade 1 according to the NCI Common Toxicity Criteria
• Lack of physical integrity of the upper gastrointestinal tract
• Malabsorption syndrome
• Inability to take oral medication
• Significant traumatic injury within the past 28 days

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• More than 4 weeks since prior radiotherapy
• More than 10 days since prior and no concurrent ongoing treatment with anticoagulants for therapeutic purposes
• More than 28 days since prior and no concurrent major surgical procedure
• More than 28 days since prior open biopsy
• More than 30 days since prior investigational agents
• No concurrent chronic daily high-dose acetylsalicylic acid (> 325 mg/day)