Inclusion Criteria:

• Patients older than 18 years and less than 80 years
• Histologically-proven adenocarcinoma of the prostate
• Evidence of bone metastases and progressive, hormone-refractory, disease
• No previous chemotherapy
• No previous radiotherapy, except radiotherapy directed to the prostate and/or to a single bony lesion
• No previous carcinoma, except basal-cell carcinoma of the skin
• Adequate renal function: measured or calculated creatinine clearance > 60 ml/min
• Absolute granulocyte count ≥ 1,500/mm3, platelets ≥ 100,000 mm3, bilirubin ≤ 1.5 fold the upper normal value
• Signed informed consent.

Exclusion Criteria:

• Patients infected by the Human Immunodeficiency Virus (HIV)
• Patients who do not fit inclusion criteria