Prognostic value of neutrophil-to-lymphocyte ratio (NLR) in penile cancer: A systematic review and meta-analysis

BACKGROUND: Penile cancer is rare among male malignancies. Various biomarkers have been used to predict the prognosis of cancer, one of which is the neutrophil to lymphocyte ratio (NLR). Therefore, we conducted this systematic review and meta-analysis to evaluate the prognostic value of NLR in penile cancer. METHODS: This review was conducted following the PRISMA guideline. Several databases, including Scopus, Science-direct, and PubMed, were systematically searched. The primary outcomes were lymph node metastasis (LNM), cancer-specific survival (CSS), and overall survival (OS). All statistical analyses were processed using Review Manager (RevMan) version 5.4. RESULTS: A total of six retrospective studies were included in the analysis. The cut-off values of NLR in the included studies ranged from 2.6 to 3.59. Meta-analysis showed that penile cancer patients with high NLR had worse LNM and CSS based on the univariate analysis (OR 3.56, 95% CI 2.38, 5.32, p < 0.01; HR 4.19, 95% CI 2.19, 8.01, p = 0.0; respectively). Furthermore, the meta-analysis revealed that NLR is an independent predictor of LNM and CSS (OR 6.67, 95% CI 2.44, 18.22, p < 0.01; HR 2.15, 95% CI 1.23, 3.73, p < 0.01; respectively). However, NLR failed to show as independent predictor for OS (HR 1.69,95% CI 0.95,3.00, p = 0.07). CONCLUSION: NLR is an independent predictor of LNM and CSS. However, NLR is not proven to be an independent predictor of OS in this study.