Methylprednisolone With or Without Doxorubicin in Treating Patients With Metastatic Prostate Cancer

DISEASE CHARACTERISTICS: Histologically proven, symptomatic prostate cancer Appearance or aggravation of clinical symptoms with progression of disease Bone pain OR Urethral compression OR 20% decrease in performance status Metastatic disease Local-regional or distant secondary tumors Documented radiologically or scintigraphically Hormone-refractory as defined by progression while on hormone treatment (simple castration or complete androgen blockage) Progressive disease No urethral or cervical stenosis Increase of greater than 25% prostatic volume on endorectal echography No documentation by PSA increase or imagery only Hormone castration verified by testosterone less than 0.5 ng/mL No history of CNS metastases PATIENT CHARACTERISTICS: Age: Over 18 Performance status: Karnofsky 60-100% Life expectancy: No specified Hematopoietic: Neutrophil count greater than 1500/mm3 Platelet count greater than 100,000/mm3 Hemoglobin greater than 9 g/dL Hepatic: Bilirubin less than 1.5 times normal Renal: Creatinine less than 1.6 mg/dL Cardiovascular: Ventricular ejection fraction at least 50% Other: No contraindication to anthracycline treatment No prior primary cancer except basal cell skin cancer PRIOR CONCURRENT THERAPY: Biologic therapy: Not specified Chemotherapy: No prior chemotherapy Arm I: No concurrent chemotherapy Endocrine therapy: At least 1 month since prior hormone therapy, including estramustine, except LHRH agonists, which continue Arm I: No concurrent estramustine Radiotherapy: At least 3 months since prior strontium 89 No concurrent strontium Surgery: See Disease Characteristics