Role of Liquid Biopsy in Clinical Decision-Making for Breast Cancer

Purpose of Review: Liquid biopsies are easily obtainable, non-invasive, longitudinal snapshots that can be used to measure micrometastatic disease burden, monitor disease progression, and provide genomic assessments of primary tumor/metastatic lesions. To date, most published studies have focused on circulating tumor cells (CTCs) and cell-free circulating tumor DNA (ctDNA); however, the liquid biopsy field is expanding exponentially and new blood components are currently under investigation. Recent Findings: CTCs and ctDNA remain the most extensively studied liquid biopsy components to date. Several additional blood-based components are the basis of active, ongoing investigations. Some on the horizon include serum/plasma exosomes, platelet-mRNA, miRNA characterization, and global proteomic studies. Summary: In the era of individualized medicine, liquid biopsy has potential to improve upon current breast cancer management by offering dynamic monitoring possibilities as well as novel targets for therapy.