Liquid biopsy for guiding breast cancer immunotherapy

Liquid biopsy is a laboratory test used to detect and analyze circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and other tumor-derived components, in a blood sample. In the context of breast cancer (BC), liquid biopsies hold significant promise for guiding the use of immune checkpoint inhibitors and immune-based combinations, offering real-time insights into tumor dynamics, treatment response, and resistance mechanisms. This review explores the role of liquid biopsy in BC immunotherapy, focusing on its applications, benefits, issues, and current and future research directions.