Does docetaxel prolong survival of patients with non‐metastatic castration‐resistant prostate cancer?

Background Guidelines define docetaxel as a first‐line therapeutic option for metastatic castration‐resistant prostate cancer (mCRPC). However, the role of docetaxel in non‐metastatic castration‐resistant prostate cancer (nmCRPC) has not been fully investigated. The aim of this retrospective study was to evaluate the potential role of docetaxel in nmCRPC. Clinical outcomes including overall survival were compared between CRPC patients who had docetaxel introduced while in nonmetastatic versus metastatic diseases. Methods A total of 98 CRPC patients had docetaxel therapy. Of these 46 patients received docetaxel for nmCRPC, and 52 had distant metastases. Clinical outcomes from the time of diagnosis of CRPC were compared retrospectively between groups. Results The median observation period after the diagnosis of CRPC in these patients was 42 months (range, 3‐166). Overall survival (OS) was significantly longer in the nmCRPC group than in the mCRPC group (not reached vs 52.2 months, respectively, P = 0.006). Multivariate analysis showed that longer time to CRPC, docetaxel use in nmCRPC, and use of abiraterone acetate and/or enzalutamide were significant predictors for improved OS (P = 0.04, 0.019 and 0.002, respectively). The incidence and profile of adverse events did not differ significantly between groups. Conclusions Earlier induction of docetaxel in nmCRPC patients may prolong OS. Further prospective studies in more patients will be required to confirm our findings.