DISEASE CHARACTERISTICS:

• Histologically confirmed adenocarcinoma of the prostate

  • Stage D1 or D2 disease (T4, N0, M0; any T, N1-3, M0; or any T, any N, M1)

• Unresponsive or refractory to prior hormonal therapy by at least 1 of the following:

  • Progression of unidimensionally measurable lesion outside of a prior radiation port
  • Progression of non-measurable disease (e.g., bone scan)
• Rising prostate-specific antigen (PSA) on at least 2 consecutive measurements taken at least 7 days apart
• PSA at least 5 ng/mL
• No brain metastases

PATIENT CHARACTERISTICS:

Age:

• Not specified

Performance status:

• Zubrod 0-2

Life expectancy:

• Not specified

Hematopoietic:

• Absolute granulocyte count at least 1,500/mm^3
• Platelet count at least 100,000/mm^3

Hepatic:

• Bilirubin no greater than upper limit of normal (ULN)
• SGOT or SGPT no greater than 2.5 times ULN

Renal:

• Creatinine no greater than 2.0 mg/dL OR
• Creatinine clearance at least 40 mL/min

Other:

• No other malignancy within the past 5 years except adequately treated squamous cell or basal cell skin cancer, any carcinoma in situ, or stage I or II cancer in complete remission
• No other concurrent significant active illness that would preclude study participation
• Recovered from major infections
• Fertile patients must use effective contraception

PRIOR CONCURRENT THERAPY:

Biologic therapy:

• At least 28 days since prior biologic therapy and recovered
• No more than 1 prior biologic (non-cytotoxic) therapy
• No concurrent biological response modifiers

Chemotherapy:

• No prior chemotherapy for this disease
• No other concurrent chemotherapy

Endocrine therapy:

• See Disease Characteristics
• At least 28 days since prior flutamide or ketoconazole
• At least 42 days since prior bicalutamide or nilutamide
• No concurrent hormonal therapy, except luteinizing hormone-releasing hormone therapy
• No concurrent corticosteroids

Radiotherapy:

• See Disease Characteristics
• Prior radiotherapy to less than 30% of bone marrow allowed
• No prior strontium chloride Sr 89 or samarium Sm 153 lexidronam pentasodium
• At least 28 days since prior radiotherapy and recovered
• No concurrent radiotherapy

Surgery:

• Recovered from prior surgery
• Prior orchiectomy allowed

Other:

• No concurrent unconventional therapy (e.g., St. John's Wort, PC-SPES, or other herbal remedy for prostate cancer)
• Not planning to begin bisphosphonate therapy (patients already receiving bisphosphonates are eligible provided they have progressive disease)