Abstract
De novo metastatic breast cancer (dnMBC) represents a minority of MBC cases, and as such, its genomics are poorly understood. Characterizing the genomics of dnMBC represents an opportunity to delineate metastatic drivers in the absence of treatment selection. In this review, we first summarize the literature of the genomics of MBC which showed that MBCs have greater mutational burden than early stage, treatment naïve breast cancers. We then turn to recent studies that have sought to focus on dnMBC. We propose that understanding genomic differences between dnMBC and relapsed MBC can inform treatment choices. Finally, we discuss translational strategies to better dissect the genomics of dnMBC.