DISEASE CHARACTERISTICS:

• Histologically confirmed prostate cancer

  • Metastatic disease, as demonstrated by bone scan and/or CT scan of the abdomen/pelvis
  • Must demonstrate disease progression after initial hormone therapy (including bicalutamide and flutamide)
  • No prior chemotherapy allowed
• No known brain metastases

PATIENT CHARACTERISTICS:

• ECOG performance status 0-1
• Life expectancy ≥ 6 months
• ANC > 1,500/μL
• Hemoglobin > 10 g/dL
• Platelet count > 100,000/mm^3
• Serum creatinine < 2.0 mg/dL or creatinine clearance > 50 mL/min
• Total bilirubin normal
• SGOT and/or SGPT < 1.5 times upper limit of normal (ULN)
• Alkaline phosphatase < 2.5 times ULN
• Fertile patients must use effective contraception during and for 3 months after completion of study therapy
• No second primary malignancy except for most in situ carcinomas (e.g., adequately treated nonmelanoma carcinoma of the skin) or other malignancy treated ≥ 5 years ago with no evidence of recurrence

• No history or symptoms of cardiovascular disease, including any of the following:

  • NYHA class II-IV cardiovacular disease within the past 6 months
  • Coronary artery disease
  • Arrhythmias
  • Conduction defects with risk of cardiovascular instability
  • Uncontrolled hypertension
  • Clinically significant pericardial effusion
  • Congestive heart failure
• No uncontrolled intercurrent illness including ongoing active infection that would limit compliance with study requirements
• No rheumatoid arthritis or systemic lupus erythematosus requiring treatment
• No psoriasis or porphyria
• No known HIV infection
• No hypersensitivity to 4-aminoquinoline compounds, including hydroxychloroquine sulfate, chloroquine phosphate, and amodiaquine
• No retinal or vision changes from prior 4-aminoquinoline compound use
• No history of severe hypersensitivity reaction to docetaxel or other drugs formulated with polysorbate 80
• No known G-6PDH deficiency
• Neurotoxicity ≤ grade 1

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Recovered from all prior therapy
• No prior taxane
• At least 4 weeks since prior therapy (including surgery and radiotherapy)
• At least 1 week since prior herbal supplements
• At least 6 weeks since prior bicalutamide
• At least 4 weeks since prior flutamide

• No current hydroxychloroquine for treatment or prophylaxis

  • Prior hydroxychloroquine allowed
• No other concurrent investigational or commercial agents or therapies, including chemotherapy, immunotherapy, hormonal cancer therapy, radiotherapy, surgery for cancer, or experimental therapy
• Concurrent luteinizing-hormone releasing-hormone agonists allowed