The taxoid analogue docetaxel is a potent inhibitor of microtubular depolymerisation and, in hormone-refractory metastatic prostate cancer, it also counters the effects of the anti-apoptotic protein Bcl-2. Overall survival was significantly increased in patients with hormone-refractory metastatic prostate cancer receiving intravenous docetaxel every 3 weeks plus oral prednisone or estramustine, compared with patients receiving intravenous mitoxantrone every 3 weeks plus prednisone in two large phase III trials (TAX 327 and SWOG [Southwest Oncology Group] 9916). In the TAX 327 study, patients receiving docetaxel 75 mg/m(2) every 3 weeks plus prednisone had a median overall survival duration of 18.9 months; in the SWOG 9916 study, median overall survival duration was 17.5 months with docetaxel 60 mg/m(2) every 3 weeks plus estramustine 280 mg three times daily on days 1-5. The median overall survival duration for the control arm of mitoxantrone 12 mg/m(2) every 3 weeks plus prednisone was 16-17 months. Compared with mitoxantrone plus prednisone, docetaxel plus prednisone improved prostate specific antigen response rate, pain and health-related quality of life, and docetaxel plus estramustine increased progression-free survival. Adverse events were more common with docetaxel- than mitoxantrone-based treatment regimens, but most events associated with docetaxel were mild-to-moderate in severity.