In recent years, immune checkpoint inhibitors have rapidly changed treatment paradigms and have been pivotal for the treatment of advanced NSCLC patients. However, many patients don't respond to immunotherapy, and toxicities are a concern. Mounting evidence suggests that PD-L1 expression and tumor mutational burden are useful biomarkers in NSCLC and widely used in clinical practice. Given various limitations of PD-L1 and tumor mutational burden, many candidate biomarkers have emerged. From these biomarkers, peripheral blood-based biomarkers are promising options for the prediction of immunotherapy efficacy with ease of access, repeatability and low cost. This review provides an overview of recent developments on the biomarkers in immunotherapy efficacy together with comments on future perspectives.
Keywords: PD-L1; biomarkers; immunotherapy; liquid biopsy; non-small-cell lung cancer; tumor mutational burden.