DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

• Failure of complete androgen ablation (orchiectomy or LHRH and antiandrogen therapy) as manifested by at least 1 of the following criteria:

  • Rise in serum PSA greater than 50% of nadir confirmed on 2 measurements 1 week apart
  • Appearance of new lesions on bone scan
  • Appearance of new soft-tissue lesions
• Measurable or evaluable disease
• No brain or leptomeningeal involvement

PATIENT CHARACTERISTICS:

Age:

• 18 and over

Performance status:

• ECOG 0-2

Life expectancy:

• Greater than 3 months

Hematopoietic:

• WBC at least 3,500/mm3
• Absolute neutrophil count at least 1,500/mm3
• Platelet count at least 100,000/mm3

Hepatic:

• Bilirubin no greater than upper limit of normal (ULN)
• Alkaline phosphatase no greater than 5 times ULN
• SGOT and SGPT no greater than 2 times ULN

Renal:

• Creatinine no greater than 2 times ULN

Cardiovascular:

• No history of coagulopathy
• No myocardial infarction in the last 6 months
• No history of cardiovascular accident
• No history of congestive heart failure

Neurological:

• No symptomatic peripheral neuropathy greater than grade 1
• No history of significant neurologic or psychiatric disorders including psychotic disorders, dementia, or seizures

Pulmonary:

• No history of pulmonary embolus

Other:

• Testosterone no greater than 3.5 nmol/L
• No contraindications to glucocorticoid therapy such as uncontrolled diabetes mellitus or active peptic ulcer disease
• No active infection
• No other serious illness or medical condition
• No other concurrent or prior malignancy in the past 5 years except previously excised or curatively irradiated nonmelanoma skin cancer

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• At least 4 weeks since prior chemotherapy

Endocrine therapy:

• See Disease Characteristics
• At least 4 weeks since prior hormonal therapy (including nonsteroidal antiandrogens, but not LHRH agonists)

Radiotherapy:

• No prior radiotherapy to greater than 30% of bone marrow
• At least 6 weeks since isotope therapy
• At least 4 weeks since prior radiotherapy

Surgery:

• See Disease Characteristics

Other:

• At least 4 weeks since prior investigational drugs