Tumor Mutational Burden as a Predictor of Immune-Related Adverse Events in Patients With Advanced Non-Small Cell Lung Cancer Receiving Immune Checkpoint Inhibitors: A Brief Report

High tumor mutational burden (TMB) predicts not only response to immune checkpoint inhibitors (ICI) in advanced non-small cell lung cancer (NSCLC) but also immune-related toxicity. In this single-center cohort of 1,215 patients treated with ICI ± chemotherapy, higher baseline TMB was associated with an increased risk of immune-related adverse events (irAEs) and earlier onset; a very high TMB (≥19 mut/Mb, 90th percentile) was the strongest predictor of both outcomes. High‑TMB tumors were enriched for CD8+ T cells, supporting a biologically driven link between tumor immunogenicity and irAE risk. For CTSNet’s audience, the study positions very high TMB as a dual biomarker for ICI efficacy and toxicity in lung cancer, informing multidisciplinary discussions about patient selection, counseling, and monitoring of thoracic oncology patients receiving immunotherapy.