Elevated peripheral blood neutrophil-to-lymphocyte ratio is associated with an immunosuppressive tumour microenvironment and decreased benefit of PD-1 antibody in advanced gastric cancer.

Our study demonstrated the potential clinical utility of NLR as a biomarker for patient selection and clinical management in predicting the prognosis of AGC patients as well as response to anti-PD-1 therapy. In addition, high bNLR reflected the imbalance of tumour-tissue-infiltrating neutrophils and lymphocytes, and was associated with an immunosuppressive and pro-tumour microenvironment.