Prognostic role of pretreatment neutrophil-to-lymphocyte ratio (NLR) in patients with non–muscle-invasive bladder cancer (NMIBC): A systematic review and meta-analysis

Objective: The aim of this study was to summarize and analyze the current evidence regarding the prognostic and predictive value of preoperative neutrophil-to-lymphocyte ratio (NLR) in patients undergoing transurethral resection of bladder tumors (TURBT) for non–muscle-invasive bladder cancer (NMIBC). Material and methods: A systematic search of Web of Science, Medline/PubMed, Google Scholar, and Cochrane library was performed on the 1^st of March, 2018. Studies were deemed eligible if they compared NMIBC patients with high vs. low NLR before TURBT to determine its value for prognosticating disease recurrence and progression using multivariable analysis. We performed a formal meta-analysis for both recurrence-free (RFS) and progression-free survival (PFS). Results: Six studies encompassing 2,298 patients (477 [20.7%] females) assessed the prognostic value of NLR in NMIBC patients treated with TURBT. NLR predicted worse RFS (pooled HR = 1.78; 95% CI: 1.32–2.4, P<0.001) and PFS (pooled HR = 2.14; 95% CI: 1.59–2.87, P<0.001). In 4 studies encompassing 599 patients, high pretreatment NLR was associated with decreased RFS (pooled HR = 2.31; 95% CI: 1.27–4.22, P = 0.006) and in 3 of them high pretreatment NLR was associated with decreased PFS (pooled HR = 2.54; 95% CI: 1.36–4.71, P = 0.003) in high-risk NMIBC patients treated with BCG. Conclusion: In this meta-analysis, peripheral blood levels of NLR were associated with an increased risk of disease recurrence and progression in patients who underwent TURBT for NMIBC. Furthermore, NLR was an independent predictor of disease recurrence and progression in NMIBC treated with BCG patients. NLR could be used to improve clinical decision-making regarding treatment and follow-up scheduling.