Prognostic utility of platelet–lymphocyte ratio, neutrophil–lymphocyte ratio and monocyte–lymphocyte ratio in head and neck cancers: A detailed prisma compliant systematic review and meta-analysis

Inflammation plays a major role in cancer development and progression apotential to be used as a prognostic marker in cancer. Previous studies have attempted Platelet-to-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR) or monocyte-lratio (MLR) as indicators of inflammation/prognostic markers in cancer, but there is nconsensus on their application in clinical practice. The aim of this systematic review and mis to (a) assess the prognostic efficacy of all three prognostic markers in comparison to eac(b) investigate the prognostic potential of these three markers in HNC. The study followguidelines, with the literature being collated from multiple bibliographic databases. Prelisecondary screening were carried out using stringent inclusion/exclusion criteria. Meta-acarried out on selected studies using CMA software and HR as the pooled effect size meof 49 studies were included in the study. The pooled HR values of PLR, NLR and MLthat they were significantly correlated with poorer OS. The pooled effect estimates for and MLR were 1.461 (95% CI 1.329–1.674), 1.639 (95% CI 1.429–1.880) and 1.002 (95% CI 0respectively. Significant between-study heterogeneity was observed in the meta-analysis The results of this study suggest that PLR, NLR and MLR ratios can be powerful prognosin head and neck cancers that can guide treatment. Further evidence from large-scale clinon patient cohorts are required before they can be incorporated as a part of the cliniPROSPERO Registration ID: CRD42019121008.