Abstract
BACKGROUND: Inflammatory cytokine markers, including the neutrophil-to-lymphocyte ratio (NLR), monocyte-lymphocyte ratio, and platelet-to-lymphocyte ratio, play important roles as prognostic markers in several solid malignancies, including prostate cancer. We previously reported the NLR as a poor prognostic marker in bladder cancer, upper-urothelial carcinoma, adrenocortical carcinoma, penile cancer, and prostate cancer. This study examined the importance of the NLR as a prognostic marker for castration-resistant prostate cancer (CRPC) patients who received abiraterone acetate or enzalutamide. METHODS: A total of 805 prostate cancer patients developed in CRPC status were enrolled in this study. Of these patients, 449 received abiraterone acetate (ABI; 188 cases) or enzalutamide (ENZ; 261 cases) treatment, and the pre-treatment NLR values of these patients were obtained. We investigated the prognosis in those with higher and lower NLR values. RESULTS: The median NLR was 2.90, and a receiver operating characteristics analysis suggested a candidate cut-off point of 3.02. The median overall survival (OS) was 17.3 months in the higher NLR group (≥3.02) and 27.3 months in the lower NLR group (< 3.02) (p < 0.0001). This trend was also observed in both the ABI and ENZ groups (ABI: 29.3 vs. 15.1 months; ENZ: NR vs. 19.5 months; p < 0.0001 and < 0.0001, respectively). A multivariate analysis revealed that a higher NLR was an independent risk factor. The NLR value was thus shown to be correlated with the prostate cancer progression. CONCLUSIONS: A higher NLR was associated with a poorer OS for CRPC patients who received ABI or ENZ. The NLR was positively correlated with prostate cancer progression.