The Diagnostic Value of Plasma Monocyte-To-Lymphocyte Ratio in Prostate Cancer and Its Metastasis: a Retrospective Clinical Study.

[BACKGROUND] This study aimed to evaluate the diagnostic value of serum inflammation markers derived from complete blood count in the diagnosis of prostate cancer (PCa).

[METHODS] We retrospectively analyzed the data of 316 patients who underwent prostate biopsy (PBx) between March 2017 and December 2019. Age, prostate specific antigen (PSA), free PSA, platelet count, neutrophil count, lymphocyte count, monocyte count, and pathology result of the patients were recorded. Patients were grouped as benign prostatic hyperplasia (BPH) and PCa. Patients were also grouped according to PSA values, Gleason scores (GS), and the status of bone metastasis.

[RESULTS] The mean monocyte-to-lymphocyte ratio (MLR) value of the patients with PCa was significantly higher than that in patients with BPH in the entire cohort (p < 0.001). In the PSA 4 - 10 ng/dL range, MLR value was significantly higher in patients with PCa than those with BPH (p = 0.040). MLR value was significantly higher in patients with GS 6 than those with GS 7 and above (p = 0.016). A receiver operating characteristic (ROC) curve analysis revealed that MLR distinguished PCa patients from BPH patients [area under the curve (AUC), 0.637; 95% CI 0.571 - 0.702; p < 0.001].

[CONCLUSIONS] MLR may be utilized as a potential novel non-invasive biomarker for PCa screening.