Weekly docetaxel/estramustine phosphate in patients with increasing serum prostate- specific antigen levels after primary treatment for prostate cancer: a phase II trial of the Minnie Pearl Cancer Research Network.

Purpose: Docetaxel alone or in combination with estramustine prolongs survival in patients with metastatic hormone-refractory prostate cancer. The role of chemotherapy is undefined in the treatment of patients who develop an increasing serum prostate-specific antigen (PSA) level after primary therapy but have no detectable metastases. This phase II study was performed as a preliminary evaluation of the feasibility and efficacy of weekly docetaxel/estramustine in patients with prostate cancer and increasing serum PSA levels.

Patients And Methods: Between March 2001 and September 2003, 34 patients entered this phase II trial. All patients had biopsy-proven adenocarcinoma of the prostate and had increasing PSA levels but no clinically or radiographically detected metastases after primary therapy. All patients received docetaxel 35 mg/m(2) intravenously on days 1, 8, and 15 and estramustine phosphate 140 mg 3 times daily for 7 doses, beginning the evening before each dose of docetaxel. Treatment courses were repeated at 28-day intervals, and responding patients received a total of 6 courses.

Results: Thirty-one patients (91%) completed 6 courses of treatment. Thirty-two of 33 evaluable patients (97%) had a decrease in serum PSA level of > 50% during treatment, and 27 patients (82%) had normalization of serum PSA level. The median progression-free survival was 28 months, with 33% of patients progression free at 3 years. This treatment regimen was well tolerated with no myelosuppression-related complications or uncommon grade 3 nonhematologic toxicity.

Conclusion: Treatment with weekly docetaxel and estramustine is feasible and active in patients with prostate cancer and increasing serum PSA levels. However, the benefit of early treatment versus treatment when clinical metastases are detected requires demonstration in a randomized phase III trial.