Advances in research on biomarkers of immune checkpoint inhibitor-related pneumonitis in non-small cell lung cancer

Abstract Lung cancer, primarily non-small cell lung cancer (NSCLC), is a major factor affecting cancer-associated deaths globally. Conventional treatments – including surgery, radiotherapy, and pharmacotherapy – are the foundational treatments. Nonetheless, introducing immune checkpoint inhibitors (ICIs) can transform cancer management by augmenting T-cell-related antitumor immunity and prolonging advanced-stage patient survival. However, by disrupting immune homeostasis, ICIs may trigger immune-related adverse events (ir-AEs). Immune checkpoint inhibitor-related pneumonitis (CIP) has aroused wide attention because it threatens human life. Although CIP occurs infrequently, it carries a substantial mortality risk and necessitates immunotherapy interruption, significantly compromising patient survival. It remains challenging to diagnose CIP due to its nonspecific clinical presentation, radiographic features, and laboratory findings. Thus, it is urgent to understand potential biomarkers for CIP in NSCLC. Identifying reliable biomarkers can help reduce CIP incidence, facilitate early diagnosis and intervention in high-risk individuals, improve patient prognosis, and optimize treatment strategies, ultimately improving patient outcomes. Therefore, this review summarizes the potential biomarkers for CIP to provide insights for its early identification.