The Clinical Use of the Neutrophil to Lymphocyte Ratio (NLR) in Urothelial Cancer: A Systematic Review

The neutrophil to lymphocyte ratio (NLR) is an inflammatory index that has been considered as a potential prognostic factor in human cancer. The aim of this study was to evaluate the available evidence regarding the NLR as a prognostic value in patients affected by urothelial cancer. This literature review, including papers on NLR in urothelial cancers, was done on PubMed/Medline and Cochrane libraries in November 2015. The selection of the articles followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses process. Twenty-three of 99 articles fulfilled all the inclusion criteria, including data on 6240 patients affected by urothelial cancers. Overall, cancer-specific, and recurrence-free survival were evaluated as the main oncological outcomes. There was significant heterogeneity among studies, and the majority of studies were of poor quality. Overall, NLR was considered as a prognostic marker in 87.5%, 80%, and 60% of the studies on upper tract urothelial cancer, urothelial bladder cancer, and metastatic and advanced disease, respectively. The NLR cut-off value ranged between 2 and 5. A high NLR was associated with worse overall, cancer-specific, and recurrence-free survival. NLR is a widely available, easy-to-collect, costless, prognostic marker in urothelial cancers. Its clinical use still remains under investigation, especially for the need for cut-off values, particularly in different subsets of patients.