Purpose: Androgen-deprivation therapy (ADT) is effective for relapsed prostate cancer, but is rarely curative. The purpose of this trial was to determine the feasibility, toxicity, and prostate-specific antigen (PSA) response of chemotherapy and limited ADT for men with PSA relapse.
Patients and methods: Eligible men had an increasing PSA and no metastases after prostatectomy and/or radiation for localized disease. Treatment consisted of four cycles of docetaxel (70 mg/m2) every 21 days and estramustine 280 mg tid on days 1 through 5. After chemotherapy, goserelin acetate and bicalutamide were prescribed for 15 months.
Results: Sixty-two patients were enrolled. A complete PSA response (CR) was defined as PSA at or below the assay-specific lower limit. The proportion of patients with CR after chemotherapy, after ADT, and at 1 year after completion of ADT was 53%, 63%, and 36%, respectively. Testosterone was more than 100 ng/dL (median, 250 ng/dL) 1 year after completion of ADT in 97% of patients. Patients with a PSA less than 3.0 ng/mL at enrollment had a significantly longer time to progression (TTP; P = .0004). Of 56 patients who were observed at least 1 year after completion of ADT, 23 (41%) have not experienced progression as of their last follow-up. The median TTP is 34 months from treatment initiation (maximum, 74 months free from progression).
Conclusion: Chemotherapy plus ADT was feasible for early prostate cancer relapse. Forty-one percent of men who are at least 1 year after completion of ADT with recovered testosterone have not experienced progression. This approach is being tested in a randomized trial with investigation of predictors of response.