Tumor Molecular Profiling for ICI Therapy

All tumor samples from the MIND cohort were analyzed by next-generation sequencing (NGS) before ICI treatment [23 (link)]. The test method was performed on the U.S. Food and Drug Administration-licensed Memorial Sloan Kettering Cancer Center’s Integrated Mutation Profiling of Actionable Cancer Targets platform, which includes somatic mutations, copy number alterations, and fusions of 341–468 genes most commonly associated with cancer. Based on NGS profiling in patients from the MIND cohort, we defined a TMB of ≥ 10 mutations (muts)/Mb as “high TMB” and TMB < 10 muts/Mb as “low TMB.” PD-L1 immunohistochemistry was performed on formalin-fixed and paraffin-embedded tumor tissue sections using standard PD-L1 antibody (E1L3N; Cell Signaling Technology, Danvers, Massachusetts, USA). The tumor cells were considered to have a high PD-L1 expression level when ≥ 50% of the cells stained positively.