Chemokine Receptors in Peripheral Blood Mononuclear Cells as Predictive Biomarkers for Immunotherapy Efficacy in...

Non-small cell lung cancer (NSCLC) remains a leading cause of cancer-related mortality globally. The advent of immune checkpoint inhibitors (ICIs) has significantly improved outcomes for a subset of patients; however, predictive biomarkers to identify responders are still lacking. Peripheral blood mononuclear cells (PBMCs) offer a minimally invasive means to assess systemic immune status and have emerged as a potential source of predictive biomarkers. Recent studies have highlighted the role of chemokines and their receptors in modulating immune responses against tumors. In particular, the expression levels of chemokine receptors such as CXCR4 on PBMCs have been associated with patient responses to ICIs. The differences in expression of these receptors correlates with enhanced T cell trafficking and infiltration into the tumor microenvironment, leading to improved antitumor activity. This review consolidates current evidence on the prognostic and predictive value of chemokine receptor expression in PBMCs, like T cells, for NSCLC patients treated with ICIs. Understanding these associations can aid in the development of non-invasive biomarkers to guide treatment decisions and improve patient stratification in immunotherapy.