Prognostic role of pretreatment blood neutrophil-to-lymphocyte ratio in advanced cancer survivors: A systematic review and meta-analysis of 66 cohort studies.

Neutrophil-to-lymphocyte ratio (NLR) is crucial for the incidence and mortality of various tumors. However, little is known on NLR and its association with prognosis in advanced tumors. Here we performed a meta-analysis to establish the prognostic significance of pretreatment blood NLR for advanced tumors.