PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy for metastatic disease Endocrine therapy: See Disease Characteristics Hormonal therapy (except antiandrogens like LHRH) must be continued Radiotherapy: No prior radiotherapy for metastatic disease including strontium chloride Sr 89 Surgery: No prior splenectomy Other: No prior ketoconazole At least 4 weeks since prior immunosuppressives (e.g., prednisone or hydrocortisone) No prior investigational agents No concurrent medication that may affect immune function except nonprescription strength doses of nonsteroidal anti-inflammatory drugs, acetaminophen, or aspirin; low doses of antihistamine; normal doses of vitamins; or H2 blockers No more than 2 short courses (no more than 10 days per course) of antibiotics for treatment of minor infection in a 45 day span