Liquid biopsy in cancer drug resistance: real-time monitoring, mechanistic insights, and translational applications

Liquid biopsy provides a non-invasive approach for cancer detection. It examines tumor-associated components in blood and other body fluids, including circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vesicles (EVs, including exosomes). This technology is transforming cancer diagnosis, prognosis, and therapy monitoring. This review summarizes recent advancements in liquid biopsy technologies, particularly focusing on circulating tumor components such as ctDNA, CTCs, and EVs. This review emphasizes the role of liquid biopsy in the early detection of drug resistance and therapeutic response monitoring. A primary emphasis is on how liquid biopsy detects various forms of drug resistance. It evaluates treatment efficacy, monitors alterations in tumor genomics over time, and assists in customizing therapy for people. We also discuss the integration of liquid biopsy with innovative technologies such as artificial intelligence and big data. The objective is to provide practical guidance for the future development of precision oncology.