Optimal sequencing strategy using docetaxel and androgen receptor axis-targeted agents in patients with castration-resistant prostate cancer: utilization of neutrophil-to-lymphocyte ratio

Purpose To investigate the prognostic value of neutrophil-to-lymphocyte ratio (NLR) for the selection of the optimal sequencing strategy using docetaxel and androgen receptor axis-targeted (ARAT) agents in patients with M0 or M1 castration-resistant prostate cancer (CRPC). Currently, there is a need to identify biomarkers to guide optimal sequential treatment in CRPC. Methods This multicenter, retrospective analysis included 303 consecutive patients initially diagnosed with M0 or M1 CRPC between September 2009 and March 2017. Of these, 52 (17.2%) patients received pre-docetaxel ARAT agents and 189 (62.4%) patients received post-docetaxel ARAT agents. The prognostic ability of NLR at CRPC diagnosis regarding radiographic progression-free survival (rPFS) and cancer-specific survival (CSS) were investigated. For the analysis, the NLR level was dichotomized at 2.5, and evaluated according to sequencing strategy. Results Multivariate analysis revealed NLR >= 2.5 as an independent predictor of a lower risk for CSS. During the median follow-up of 18.5 months, patients with NLR >= 2.5 exhibited significantly lower 1-year rPFS (p = 0.011) and 2-year CSS rates (p = 0.005) compared to patients with NLR < 2.5. Among patients with NLR < 2.5, the post-docetaxel ARAT agent sequencing group exhibited higher 1-year rPFS (p = 0.031) and 2-year CSS (p = 0.026) rates compared to the pre-docetaxel ARAT agent sequencing group. Among patients with NLR >= 2.5, rPFS and CSS rates were comparable regardless of ARAT agent sequencing. Conclusion NLR >= 2.5 at CRPC diagnosis is associated with a lower risk for CSS. Patients with NLR < 2.5 should primarily be offered docetaxel considering the survival benefit of docetaxel-to-ARAT agent sequencing.