DISEASE CHARACTERISTICS:

• Histologically or cytologically confirmed stage IV hormone refractory adenocarcinoma of the prostate
• Progressive disease despite hormonal therapy or orchiectomy
• No brain metastases

PATIENT CHARACTERISTICS:

Age:

• 18 to 80

Performance status:

• WHO 0-2

Life expectancy:

• At least 3 months

Hematopoietic:

• Absolute neutrophil count at least 2,000/mm^3
• Platelet count greater than 100,000/mm^3
• Hemoglobin greater than 9 g/dL

Hepatic:

• Alkaline phosphatase no greater than 2 times upper limit of normal (ULN) (unless bone metastasis)
• Bilirubin less than 2 times ULN

Renal:

• Creatinine less than 2 times ULN

Cardiovascular:

• Adequate cardiac function

Other:

• No other prior malignancy except curatively treated basal or squamous cell skin cancer or carcinoma in situ of the cervix

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• Not specified

Chemotherapy:

• No prior chemotherapy

Endocrine therapy:

• See Disease Characteristics
• Prior corticosteroids allowed if started at least 8 weeks prior to study

Radiotherapy:

• At least 8 weeks since prior extensive radiotherapy

Surgery:

• See Disease Characteristics