Purpose: The aim of this study was to evaluate the efficacy and safety of zoledronic acid (ZA) in the combination of docetaxel-based chemotherapy for castration-resistant prostate cancer with bone metastases.
Methods: We conducted a prospective study in recruiting 105 prostate cancer patients with bone metastases from 2008 to 2010. Patients were randomly divided into two groups, 53 in the docetaxel-based chemotherapy + ZA(Group A) and 52 in the docetaxel-based chemotherapy + placebo(Group B). The different outcome between patients treated with chemotherapy combined with ZA and those with chemotherapy alone was evaluated. The Cox multivariate analyses of clinical features and different treatment methods of the 105 patients were conducted.
Results: There was a response of prostate-specific antigen (PSA) in 33 (62.3 %) in Group A and 28 (53.8 %) in Group B (P = 0.20). The combined approach group had better bone progression-free survival (BPFS) (9.0 vs. 6.0 months, P < 0.05) and overall survival (OS) (19.0 vs. 15.0 months, P = 0.02), but no statistical evidence of benefit was observed in terms of PSA response. Cox multivariate analysis identified the following independent prognostic factors: received ZA, high Hb level and more than 6 cycles of chemotherapy. There were no clinical relevant differences in the frequencies of adverse events between these two groups.
Conclusions: Zoledronic acid treatment combined with docetaxel-based chemotherapy could have a better bone pain control and improve BPFS and OS for prostate cancer patients with bone metastases. The PSA response and SREs rate are similar.