Effect of Adding Docetaxel to Androgen-Deprivation Therapy in Patients With High-Risk Prostate Cancer With Rising Prostate-Specific Antigen Levels After Primary Local Therapy: A Randomized Clinical Trial

Importance: Androgen-deprivation therapy (ADT) plus docetaxel is the standard of care in hormone-naive metastatic prostate cancer but is of uncertain benefit in a nonmetastatic, high-risk prostate cancer setting.

Objective: To assess the benefit of ADT plus docetaxel in patients presenting with rising prostate-specific antigen (PSA) levels after primary local therapy and high-risk factors but no evidence of metastatic disease.

Design, Setting, And Participants: This open-label, phase 3, randomized superiority trial comparing ADT plus docetaxel vs ADT alone enrolled patients from 28 centers in France between June 4, 2003, and September 25, 2007; final follow-up was conducted April 12, 2017, and analysis was performed May 2 to July 31, 2017. Patients had undergone primary local therapy for prostate cancer, were experiencing rising PSA levels, and were considered to be at high risk of metastatic disease. Stratification was by prior local therapy and PSA-level doubling time (≤6 vs >6 months), and intention-to-treat analysis was used.

Interventions: Patients were randomly assigned to receive ADT (1 year) plus docetaxel, 70 mg/m2 (every 3 weeks [6 cycles]), or ADT alone (1 year).

Main Outcomes And Measures: The primary outcome was PSA progression-free survival (PSA-PFS). Secondary end points were PSA response, radiologic PFS, overall survival, safety, and quality of life.

Results: Overall, 254 patients were randomized (1:1) to the trial; median age, 64 years in the ADT plus docetaxel arm, 66 years in the ADT alone arm. At a median follow-up of 30.0 months, the median PSA-PFS was 20.3 (95% CI, 19.0-21.6) months in the ADT plus docetaxel arm vs 19.3 (95% CI, 18.2-20.8) months in the ADT alone arm (hazard ratio [HR], 0.85; 95% CI, 0.62-1.16; P = .31). At a median follow-up of 10.5 years, there was no significant between-arm difference in radiologic PFS (HR, 1.03; 95% CI, 0.74-1.43; P = .88). Overall survival data were not mature. The most common grade 3 or 4 hematologic toxic effects in the ADT plus docetaxel arm were neutropenia (60 of 125 patients [48.0%]), febrile neutropenia (10 [8.0%]), and thrombocytopenia (4 [3.0%]). There was no significant between-arm difference in overall quality of life.

Conclusions And Relevance: Compared with ADT alone, combined ADT plus docetaxel therapy with curative intent did not significantly improve PSA-PFS in patients with high-risk prostate cancer and rising PSA levels and no evidence of metastatic disease.

Trial Registration: French Health Products Safety Agency identifier: 030591; ClinicalTrials.gov identifier: NCT00764166.