Liquid biopsy is a noninvasive method for detecting tumor-related information in body fluids, offering advantages over traditional tissue biopsy in cancer screening, monitoring, and treatment. It enables the detection of circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vesicles (EVs), which provide insights into tumor progression, treatment response, and prognosis. Liquid biopsy is particularly valuable in immunotherapy and targeted therapy, where it can guide personalized treatment strategies and predict treatment outcomes. However, challenges remain in standardizing detection methods and ensuring clinical reliability. This review summarizes the clinical applications of liquid biopsy in cancer screening, monitoring, and treatment, highlighting its potential to improve early detection, monitor disease progression, and guide therapeutic decisions. Liquid biopsy has shown promise in detecting early-stage cancers, monitoring treatment response, and identifying resistance mechanisms. Despite its potential, further research is needed to refine detection techniques and expand its clinical utility. The review emphasizes the importance of liquid biopsy in advancing individualized cancer therapy and improving patient outcomes.Liquid biopsy is a noninvasive method for detecting tumor-related information in body fluids, offering advantages over traditional tissue biopsy in cancer screening, monitoring, and treatment. It enables the detection of circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), and extracellular vesicles (EVs), which provide insights into tumor progression, treatment response, and prognosis. Liquid biopsy is particularly valuable in immunotherapy and targeted therapy, where it can guide personalized treatment strategies and predict treatment outcomes. However, challenges remain in standardizing detection methods and ensuring clinical reliability. This review summarizes the clinical applications of liquid biopsy in cancer screening, monitoring, and treatment, highlighting its potential to improve early detection, monitor disease progression, and guide therapeutic decisions. Liquid biopsy has shown promise in detecting early-stage cancers, monitoring treatment response, and identifying resistance mechanisms. Despite its potential, further research is needed to refine detection techniques and expand its clinical utility. The review emphasizes the importance of liquid biopsy in advancing individualized cancer therapy and improving patient outcomes.