Abstract
Background:
Tumor mutational burden (TMB) has emerged as an imperfect biomarker of immune checkpoint inhibition (ICI) outcomes in solid tumors. Despite the approval for pembrolizumabin all TMB-high (TMB-H) solid tumors, the optimal clinical approach to TMB-H advanced/metastatic breast cancer (MBC) is unknown with sparse prospective data.
We hypothesized that TMB-H MBC will have unique genomic alterations, mutational signatures, and immune profiles compared to TMB-low (TMB-L) breast cancer that could inform novel therapeutic approaches.