High Neutrophil-to-lymphocyte Ratio Predicts Poor Clinical Outcome in Patients with Castration-resistant Prostate Cancer Treated with Docetaxel Chemotherapy

Objective: To evaluate the prognostic significance of the neutrophil-to-lymphocyte ratio in patients receiving chemotherapy with docetaxel for castration-resistant prostate cancer.

Methods: A total of 57 castration-resistant prostate cancer patients treated between 2009 and 2014 were included in the present retrospective study. All patient data, including clinicopathological factors, were assessed. Univariate and multivariate Cox regression models were used to predict overall survival and progression-free survival after chemotherapy initiation.

Results: The median overall survival and progression-free survival were determined as 19.0 months (range 1-61 months) and 10.0 months (range 1-56 months), respectively. The cut-off level of the neutrophil-to-lymphocyte ratio was set as the median value of 3.5 among all patients in this study. In Kaplan-Meier analysis, the median overall survival and progression-free survival were shorter in patients with a high neutrophil-to-lymphocyte ratio compared with those with a low neutrophil-to-lymphocyte ratio (15 vs 20 months, P = 0.0125; and 9.5 vs 15 months, P = 0.0132, respectively). The overall survival and progression-free survival periods in patients with a high neutrophil-to-lymphocyte ratio were significantly shorter than those of patients with a low neutrophil-to-lymphocyte ratio (P = 0.0178 and 0.0176, respectively). In the multivariate analysis, a high neutrophil-to-lymphocyte ratio was an independent predictor of overall survival and progression-free survival (hazard ratio 2.728, 95% confidence interval 1.05-7.09, P = 0.039; and hazard ratio 2.376, 95% confidence interval 1.12-5.06, P=0.024, respectively).

Conclusion: The present study results suggest that the neutrophil-to-lymphocyte ratio is a useful prognostic factor in patients with castration-resistant prostate cancer treated by docetaxel chemotherapy. These findings might be useful in determining treatment strategies in the future.