Prospective Randomized Study Comparing Docetaxel, Estramustine, and Prednisone With Docetaxel and Prednisone in Metastatic Hormone-Refractory Prostate Cancer

Purpose To assess the efficacy and toxicity of the addition of estramustine to docetaxel (D) for the treatment of metastatic hormone-refractory prostate cancer. Patients and Methods One hundred fifty patients were randomly assigned to D alone (35 mg/m(2) on days 2 and 9, every 3 weeks) or D in combination with estramustine (D/E; 280 mg orally three times a day on days 1 to 5 and 8 to 12, every 3 weeks). All patients received prednisone (10 mg/d). The primary end point was prostate-specific antigen (PSA) response rate, which was defined as a decrease in PSA >= 50% from baseline. The study was powered to test the hypothesis that D/E would improve the PSA response rate by 25%. Results The PSA response rate was not statistically different between the two groups. PSA of less than 4 ng/mL occurred in 29 (41%) of 71 patients receiving D/E and in 17 (25%) of 69 patients receiving D (P = .05). No significant differences were found for median time to PSA progression (D/E, 6.9 months; D, 7.3 months) or median overall survival time (D/E, 19.3 months; D, 21 months). More patients had at least one grade 3 or 4 toxicity with D/E (45%) compared with D (21%; P = .005), mainly as a result of grade 3 or 4 GI toxicity (P = .05). Serious adverse events were more frequent with D/E (n = 20) than with D (n = 9; P = .04). Conclusion The addition of estramustine to weekly D does not provide any clinically relevant advantage. Both regimens are well tolerated, although the toxicity profile favors D without estramustine.