Inclusion Criteria

DISEASE CHARACTERISTICS: Histologically confirmed metastatic hormone-refractory
adenocarcinoma of the prostate gland Elevated serum acid phosphatase or PSA levels must
not be only evidence of disease Must have evidence of progressive metastatic disease
(e.g., bone, pelvic mass, lymph node, liver, or lung metastases) Radiological evidence of
hydronephrosis alone does not constitute evidence of metastatic disease Patients with bone
metastases only (i.e., lacking measurable soft tissue disease) must have PSA level of at
least 20 ng/mL Patients with soft tissue metastases and/or visceral disease must have
either bidimensionally measurable disease or a PSA level of at least 20 ng/mL Must have
had prior treatment with bilateral orchiectomy or other primary hormonal therapy (e.g.,
estrogen therapy, LHRH-blocker plus flutamide, etc.) with evidence of treatment failure No
carcinomatous meningitis or brain metastases

PATIENT CHARACTERISTICS: Age: 18 and over Performance status: ECOG 0-2 Life expectancy:
Not specified Hematopoietic: WBC at least 4,000/mm3 OR Granulocyte count at least
2,000/mm3 Platelet count greater than 100,000/mm3 No history of deep venous thrombosis
Hepatic: Bilirubin no greater than 1.5 mg/dL SGOT and SGPT no greater than 2 times normal
Renal: Creatinine no greater than 2.0 mg/dL OR Creatinine clearance at least 50 mL/min
Cardiovascular: No active angina pectoris No known New York Heart Association class II-IV
heart disease No history of myocardial infarction in the last 6 months Other: No history
of prior malignancy except if curatively treated and disease free for time period
considered appropriate for cure of specific cancer No other serious concurrent illness or
active infection Effective contraception required of all fertile patients

PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior
chemotherapy (including neoadjuvant chemotherapy) Endocrine therapy: See Disease
Characteristics At least 6 weeks since prior bicalutamide At least 4 weeks since prior
flutamide or nilutamide Recovered from prior toxicities of endocrine therapy Radiotherapy:
No prior strontium 89, samarium 153, or other radioisotope therapies At least 4 weeks
since prior radiotherapy and recovered Surgery: See Disease Characteristics Recovered from
prior surgery