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.