Correlation of Immune Cells and Cytokines in the Tumor Microenvironment with Elevated Neutrophil-To-Lymphocyte Ratio in Blood: An Analysis of Muscle-Invasive Bladder Cancer

We investigated the relationship between Neutrophil-to-lymphocyte ratio (NLR) and the quantities of neutrophil elastase, CD3, Foxp3, and CD204 in tumor-infiltrating cells and circulating cytokines (IL-2, -6, -8, 17a, and TGF-β) in muscle-invasive bladder cancer. IL-6 and IL-8 levels showed a significant correlation with NLR in blood and Foxp3+ cells around the tumor. After co-culture of peripheral blood cells with bladder cancer cell lines, the induction of regulatory T cell (Treg) was higher in T24 whose IL-6 and IL-8 levels were higher. High NLR correlates with increased IL-6 and IL-8 and Treg expression.