Cetuximab and Bevacizumab as First-Line Therapy Followed By Combination Chemotherapy and Bevacizumab With or Without Cetuximab as Second-Line Therapy in Treating Patients With Stage IV Colorectal Cancer

DISEASE CHARACTERISTICS:

* Histologically confirmed stage IV colorectal cancer
* Measurable disease, defined as at least one lesion whose longest diameter can be accurately measured as ≥ 2.0 cm by conventional techniques OR ≥ 1.0 cm by spiral CT scan
* Must not be a candidate for neoadjuvant therapy
* No CNS or brain metastases

PATIENT CHARACTERISTICS:

* ECOG performance status 0-2
* Life expectancy ≥ 12 weeks
* ANC ≥ 1,500/mm\^3
* Platelet count ≥ 100,000/mm\^3
* Hemoglobin ≥ 10.0 g/dL
* Total bilirubin \< 1.5 times upper limit of normal (ULN)
* Alkaline phosphatase ≤ 3 times ULN
* AST ≤ 3 times ULN
* Creatinine ≤ 1.5 x times ULN
* Proteinuria \< 1+ by urinalysis OR proteinuria \< 1 g by 24-hour urine collection
* Not pregnant or nursing
* Negative pregnancy test
* Fertile patients must use effective contraception
* English-speaking patients must have the ability to complete questionnaires by themselves or with assistance
* Must be willing to provide blood and tissue samples for research purposes
* No history of hypertensive crisis or hypertensive encephalopathy
* No blood pressure \> 150/100 mm Hg
* No New York Heart Association (NYHA) class II-IV congestive heart failure
* No myocardial infarction or unstable angina within the past 6 months
* No stroke or transient ischemic attack within the past 6 months
* No clinically significant vascular disease (e.g., aortic aneurysm or aortic dissection)
* No clinically significant peripheral vascular disease
* No evidence of bleeding diathesis or coagulopathy
* No significant traumatic injury within the past 28 days
* No abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within the past 6 months
* No serious nonhealing wound, ulcer, or bone fracture

PRIOR CONCURRENT THERAPY:

* No prior nonsurgical treatment for stage IV disease

  * Adjuvant therapy allowed if completed \> 6 months prior to study registration
* More than 4 weeks since prior and no concurrent or planned participation in another experimental drug study
* No prior therapy that specifically and directly targets the EGFR pathway
* No prior monoclonal antibody therapy
* More than 28 days since prior major surgery or open biopsy
* More than 7 days since prior minor surgery, such as fine-needle aspirations or core biopsies

  * Placement of a vascular access device does not have to meet this criterion
* No concurrent major surgery