Evaluation of neutrophil-to-lymphocyte ratio prior to prostate biopsy to predict biopsy histology: Results of 1836 patients

Introduction: We evaluate the role of NLR prior to prostate biopsy to predict biopsy histology and Gleason score in patients with prostate cancer. Methods: In this retrospective study, we evaluated data of patients underwent prostate biopsy between May 2005 and March 2015. We collected the following data: age, prostate-specific antigen (PSA), biopsy histology, Gleason score (GS) in prostate cancer patients, neutrophil counts, and lymphocyte counts. Patients were grouped as benign prostatic hyperplasia (BPH), prostate cancer, and prostatitis. The Chi square test was used to compare categorical variables and analysis of variance (ANOVA) was applied for continuous variables. Results: Data of 1836 patients were investigated. The mean age, total PSA and neutrophil-lymphocyte ratio (NLR) of the population were 66.8 +/- 8.17 years, 9.38 +/- 4.7 ng/dL, and 3.11 +/- 1.71, respectively. Patients were divided as follows: 625 in the group with BPH history, 600 in the prostatitis group, and 611 in the prostate cancer histology group. The mean NLR of the prostatitis group was higher compared to the prostate cancer and BPH groups (p = 0.0001). The mean NLR of the prostate cancer group was significantly higher compared to the BPH group (p = 0.002). The GS 8-10 group had a significantly higher mean NLR compared to GS 5-6 (3.64 vs. 2.54, p = 0.0001) and GS 7 (3.64 vs. 2.58, p = 0.0001) patients. Conclusions: NLR was found to differ with regard to histology of prostate biopsy and higher GS was associated with higher NLR in patients with prostate cancer. However prostatitis prevents the use of NLR in predicting prostate cancer before a prostate biopsy. Also, the retrospective nature and lack of multivariate analysis in this study somewhat limits the relevance of these results.