Prognostic role of platelet-to-lymphocyte ratio and neutrophil-to-lymphocyte ratio in patients with non-metastatic and metastatic prostate cancer: A meta-analysis and systematic review

Abstract

Objective: To analyze data available in the literature regarding a possible prognostic value of the platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) in prostate cancer (PCa) patients stratified in non-metastatic and metastatic diseases. Methods: A literature search process was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. In our meta-analysis, the pooled event rate estimated and the pooled hazard ratio were calculated using a random effect model. Results: Forty-two articles were selected for our analysis. The pooled risk difference for non-organ confined PCa between high and low NLR cases was 0.06 (95% confidence interval [CI]: −0.03–0.15) and between high and low PLR cases increased to 0.30 (95% CI: 0.16–0.43). In non-metastatic PCa cases, the pooled hazard ratio for overall mortality between high and low NLR was 1.33 (95% CI: 0.78–1.88) and between high and low PLR was 1.47 (95% CI: 0.91–2.03), whereas in metastatic PCa cases, between high and low NLR was 1.79 (95% CI: 1.44–2.13) and between high and low PLR was 1.05 (95% CI: 0.87–1.24). Conclusion: The prognostic values of NLR and PLR in terms of PCa characteristics and responses after treatment show a high level of heterogeneity of results among studies. These two ratios can represent the inflammatory and immunity status of the patient related to several conditions. A higher predictive value is related to a high NLR in terms of risk for overall mortality in metastatic PCa cases under systemic treatments.

Keywords

• Prostatic neoplasm
• Neutrophil-to-lymphocyte ratio
• Platelet-to-lymphocyte ratio
• Meta-analysis
• Radical prostatectomy
• Metastatic