DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

• Prostate-specific antigen (PSA)-only progression despite androgen deprivation therapy, defined as 3 rising PSA levels with an interval of ≥ 2 weeks between each determination AND the most recent PSA level ≥ 1 ng/mL within the past 2 weeks

  • Patients with a second or third confirmatory PSA value less than the previous value are eligible provided a fourth PSA value is greater than all prior values
  • A withdrawl period (4 weeks for flutamide and 6 weeks for bicalutamide or nilutamide) is required to document PSA progression for patients who have been on antiandrogen therapy within the past 4 weeks
• No known CNS disease
• No evidence of metastatic disease by standard imaging (i.e., bone scan, chest x-ray or chest CT scan, and CT scan or MRI of the abdomen and pelvis)
• No known brain metastases

PATIENT CHARACTERISTICS:

• ECOG performance status 0-1
• Life expectancy ≥ 6 months
• Fertile patients must use effective contraception

• No proteinuria, defined by 1 of the following:

  • Urine protein:creatinine ratio < 1.0
  • Proteinuria < 2+ by dipstick urinalysis
  • Proteinuria ≤ 1 g by 24-hour urine collection (for patients with proteinuria ≥ 2+ by dipstick urinalysis)

• No other uncontrolled illness, including, but not limited to, any of the following:

  • Ongoing or active infection
  • Symptomatic congestive heart failure
  • Unstable angina pectoris
  • Cardiac arrhythmia
  • Psychiatric or social situation that would preclude study compliance
• No uncontrolled hypertension, defined as systolic blood pressure (BP) > 150 mm Hg and/or diastolic BP > 100 mm Hg on antihypertensive medication
• No history of hypertensive crisis or hypertensive encephalopathy
• No New York Heart Association class II-IV congestive heart failure
• No myocardial infarction or unstable angina within the past 12 months
• No stroke or transient ischemic attack within the past 6 months
• No abdominal fistula, gastrointestinal perforation, or intra-abdominal abscess within the past 6 months
• No significant traumatic injury within the past 28 days
• No significant vascular disease (i.e., aortic aneurysm or aortic dissection)
• No symptomatic peripheral vascular disease
• No evidence of bleeding diathesis or coagulopathy
• No serious nonhealing wound, ulcer, or bone fracture
• No hypersensitivity to any component of bevacizumab
• No history of allergic reactions attributed to compounds of similar chemical or biological composition to bevacizumab

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• At least 1 week since prior core biopsy or other minor surgical procedure (excluding placement of a vascular access device)
• At least 4 weeks since prior major surgical procedure or open biopsy

• At least 4 weeks since prior systemic therapy except for luteinizing hormone-releasing hormone (LHRH) analogue therapy or steroids

  • Patients receiving LHRH agonist therapy must continue LHRH agonist therapy during study participation
  • Steroids used for treatment of prostate cancer should be discontinued prior to starting bevacizumab
• No prior bevacizumab
• No concurrent major surgical procedure
• No concurrent antiretroviral therapy for patients with immune deficiencies, such as HIV
• No other concurrent investigational or commercial agents or therapies (except LHRH agonists) for this malignancy
• Concurrent anticoagulants allowed provided patient has been on therapy for at least 4 weeks and has no acute thromboembolic activity