Dexamethasone does not significantly contribute to the response rate of docetaxel and estramustine in androgen independent prostate cancer

Purpose: We evaluated the independent response rate of dexamethasone before docetaxel and estramustine administration as measured by changes in serum prostate specific antigen (PSA) in patients with androgen independent prost ate cancer. Materials and Methods: A total of 12 patients received 20 mg, dexamethasone orally every 6 hours for 3 doses repeated every 3 weeks before starting cy totoxic therapy with estramustine and docetaxel. After progression on dexam ethasone 280 mg. estramustine orally 3 times daily on days 1 to 5 and 70 mg ./m.(2) docetaxel intravenously for 1 hour on day 2 were given. Results: None of the patients initially treated with dexamethasone monother apy (median 1 cycle, range 1 to 5) had a PSA decline of 50% or greater. Med ian PSA increase on monotherapy was 47% (range 0% to 22%). On estramustine and docetaxel therapy PSA decreased 50% or greater in 11 patients (92%, 95% confidence intervals [CI] 60 to 99) and 80% or greater in 7 (58%, 95% CI 2 9 to 84), and normalized in 5 (42%, 95% CI 16 to 71), with a median duratio n of response of 153 (range 42 to 371), 132 (range 84 to 287) and 84 (range 21 to 174) days, respectively. Median times to reach 50% and 80% decreases in baseline PSA were 21 (range 21 to 209) and 63 (range 21 to 138) days, r espectively. In 9 patients (75%, 95% CI 43 to 93) PSA decreased at least 50 % by week 9, Of 4 patients with bidimensionally measurable disease 3 had a partial response. Median time to progression was 263 days (range 91 to 378) . Conclusions: Administration of 20. mg. dexamethasone orally every 6 hours f or 3 doses every 3 weeks does not significantly contribute to the PSA respo nse rate of estramustine and docetaxel.