Adjuvant Weekly Docetaxel for Patients With High Risk Prostate Cancer After Radical Prostatectomy: A Multi-Institutional Pilot Study

Purpose

Patients with adverse pathological features are at high risk for recurrence following radical prostatectomy. To improve outcomes in this population we performed a phase II study of adjuvant docetaxel in these high risk patients.

Materials and Methods

Patients with nonmetastatic radical prostatectomy at greater than 50% risk for recurrence by 3 years were eligible. Pathological findings were centrally reviewed and risk assessment was based on a validated multivariate Cox proportional hazards model. Treatment consisted of 6 cycles of 35 mg/m² docetaxel weekly given 4 to 12 weeks following surgery. Progression was defined as a prostate specific antigen of 0.4 ng/ml or greater, radiological/pathological evidence of recurrent disease or death from any cause. To screen for the potential benefit of adjuvant weekly docetaxel we used nomogram predicted progression-free survival as a historical control.

Results

A total of 77 patients were registered between April 2002 and January 2004. Two patients had grade IV hyperglycemia and 20 had grade III toxicity. At a median followup of 29.2 months (range 1.6 to 39.2) 46 of 76 evaluable cases (60.5%) progressed. Observed median progression-free survival was 15.7 months (95% CI 12.8–25.1). Predicted median progression-free survival in a matched population was 10 months. Seven patients died, including 4 of prostate cancer, 1 with intra-abdominal bleeding during treatment and 2 of pneumonia and sudden cardiac death, respectively, following treatment.

Conclusions

Adjuvant docetaxel for prostate cancer is feasible with significant reversible but acceptable toxicity. The actual median progression-free survival of 15.7 months was longer than the nomogram predicted rate for this patient population. Adjuvant docetaxel treatment should be further evaluated in phase III trials in patients with high risk prostate cancer.

Key Words: prostate, prostatic neoplasms, drug therapy, prostatectomy, mortality

Abbreviations and Acronyms: CT, computerized tomography, PFS, progression-free survival, PSA, prostate specific antigen, RP, radical prostatectomy, Rw′, weighted risk of recurrence, SWOG, Southwest Oncology Group