High Neutrophil-to-lymphocyte Ratio as Prognostic Factor in Patients Affected by Upper Tract Urothelial Cancer: A Systematic Review and Meta-analysis

Given the increasing interest in the possible role of the neutrophil-to-lymphocyte ratio (NLR) as an easily available oncologic marker for upper tract urothelial cancer (UTUC), we sought to quantify the prognostic effect of this biomarker and assess its consistency in UTUC. A systematic review of the published data was performed up to May 2016 using multiple search engines (PubMed, Ovid, and Scopus) to identify eligible comparative studies. A formal meta-analysis was performed for studies comparing patients with a high and those with a low NLR before surgical treatment of UTUC to determine whether the NLR is an independent predictor of survival. Pooled estimates were calculated using a fixed-effects model if no significant heterogeneity was identified. Alternatively, a random-effects model was used when significant heterogeneity was detected. For continuous outcomes, the weighted mean difference was used as a summary measure. For binary variables, the odds ratio or risk ratio was calculated with the 95% confidence intervals (CIs). Statistical analyses were performed using RevMan, version 5. Six studies with 1710 patients were included. A high NLR was associated with poorer oncologic outcomes in patients affected by UTUC, in particular in terms of overall survival (hazard ratio [HR], 1.97; 95% CI, 1.27-3.04; P =.002) and recurrence-free survival (HR, 1.53; 95% CI, 1.19-1.96; P =.0009) but not cancer-specific survival (HR, 1.25; 95% CI, 0.29-5.41; P =.77). Current evidence suggests that the NLR might have an independent role as a prognostic factor in patients affected by UTUC undergoing surgical treatment. The NLR potentially represents an easily available measurement of prognosis; however, it requires validation in larger prospective studies.