Predictive Value of Neutrophil to Lymphocyte Ratio in the Diagnosis of Significant Prostate Cancer at Initial Biopsy: A Comparison with Free Percent Prostate Specific Antigen, Prostate Specific Antigen Density and Primary Circulating Prostate Cells.

INTRODUCTION: An elevated serum PSA is the only biomarker routinely used in screening for prostate cancer to indicate a prostate biopsy. However, it is not specific for prostate cancer and the neutrophil/lymphocyte ratio has been suggested as an alternative. We present a prospective study of men with an elevated PSA and compare the neutrophil/lymphocyte ratio, free percent PSA, PSA density and the presence of circulating prostate cells to detect clinically significant prostate cancer at first biopsy. PATIENTS AND METHODS: Prospective study of consecutive men with a PSA 4-10 ng/ml referred for initial prostate biopsy, the results were compared with the neutrophil/lymphocyte ratio, free percent PSA and PSA density. Circulating prostate cells (CPCs) were detected using immunocytochemistry. The blood sample was taken immediately before the prostate biopsy. RESULTS: 1,223 men participated, 38% (467) of whom had prostate cancer detected, of these 322 were clinically significant. The area under the curves were for neutrophil/lymphocyte ratio, free percent PSA, PSA density and CPC detection were 0.570, 0.785, 0,620 and 0.844 respectively. Sensitivity/specificity were 0.388/0.685, 0.419/0.897, 0.598/0.624 and 0.966/0.786 respectively. The neutrophil/lymphocyte ratio did not differentiate between benign and malignant disease. CONCLUSIONS: The neutrophil/lymphocyte ratio did not discriminate between benign and malignant prostatic disease in patients with a PSA between 4-10ng/ml.