Research progress of biomarkers in the prediction of anti-PD-1/PD-L1 immunotherapeutic efficiency in lung cancer

Currently, anti-PD-1/PD-L1 immunotherapy using immune checkpoint inhibitors is widely used in the treatment of multiple cancer types including lung cancer, which is a leading cause of cancer death in the world. However, only a limited proportion of lung cancer patients will benefit from anti-PD-1/PD-L1 therapy. Therefore, it is of importance to predict the response to immunotherapy for the precision treatment of patients. Although the expression of PD-L1 and tumor mutation burden (TMB) are commonly used to predict the clinical response of anti-PD-1/PD-L1 therapy, other factors such as tumor-specific genes, dMMR/MSI, and gut microbiome are also promising predictors for immunotherapy in lung cancer. Furthermore, invasive peripheral blood biomarkers including blood DNA-related biomarkers (e.g., ctDNA and bTMB), blood cell-related biomarkers (e.g., immune cells and TCR), and other blood-related biomarkers (e.g., soluble PD-L1 and cytokines) were utilized to predict the immunotherapeutic response. In this review, the current achievements of anti-PD-1/PD-L1 therapy and the potential biomarkers for the prediction of anti-PD-1/PD-L1 immunotherapy in lung cancer treatment were summarized and discussed.

Automated summary

Currently, anti-PD-1/PD-L1 immunotherapy is widely used for treating lung cancer, but only a limited proportion of patients benefit from it. Therefore, it is important to predict the response to immunotherapy. PD-L1 expression, tumor mutation burden, tumor-specific genes, dMMR/MSI, and gut microbiome have been studied as potential predictors. In addition, invasive blood biomarkers such as ctDNA, immune cells, and cytokines have also been used. This review summarizes the achievements and potential biomarkers for predicting the response to anti-PD-1/PD-L1 immunotherapy in lung cancer.