Castration-resistant prostate cancer patients who had poor response on first androgen deprivation therapy would obtain certain clinical benefit from early docetaxel administration

Background: Our specific aim was to investigate the prognostic value of effective duration of first androgen deprivation therapy (ADT) and to evaluate the clinical impact on early docetaxel administration with oncological outcomes in castration-resistant prostate cancer (CRPC) patients treated with docetaxel. Methods: We identified 148 mCRPC patients who were treated with 75 mg/m² docetaxel. We defined 16 months as the threshold for the effective duration of ADT, and defined 12 months as the cut-off time for starting docetaxel from the onset of CRPC. Univariate and multivariate analyses were conducted to investigate the prognostic indicators that influenced the survival outcomes. Results: Overall, 81 (54.7%) patients died. The median 1st ADT response was 22.2 months and the median time interval from CRPC onset to docetaxel treatment was 11.7 months. Multivariate analysis indicated that visceral metastasis, bone metastasis extent of disease (EOD) ≥ 2, and effective duration of ADT < 16 months were the independent prognostic indicators for progression-free survival (PFS). Referring to cancer-specific survival (CSS), besides visceral metastasis and effective duration of ADT < 16 months, late docetaxel treatment ≥ 12 months became as the predictors for poor prognosis. Among the ADT poor-responder group (ADT < 16 months), Kaplan–Meier method showed that 1-year and 2-year CSS rates were 96.0% and 80.0% in the patients who introduced docetaxel in early setting (< 12 months), which were significantly higher than those who introduced in late settings (93.6% and 30.8%, respectively, p < 0.001). Conclusion: CRPC patients who had poor response during 1st ADT would obtain survival benefit by introducing docetaxel treatment in early stage.