Abstarct:

The global impact of cancer calls for the creation of quick, precise, and non-invasive methods of diagnosis. Liquid biopsy, which involves analyzing tumor-related components in bodily fluids, has become a groundbreaking asset in cancer treatment, enhancing and occasionally exceeding the capabilities of traditional tissue biopsies. This review compiles current insights on the key elements of liquid biopsy—namely, circulating tumor DNA (ctDNA), circulating tumor cells (CTCs), and extracellular vesicles (EVs)/exosomes—and their role in early cancer detection. We explore advanced analytical methods, such as next-generation sequencing (NGS) and digital PCR, which enable the sensitive identification of these rare biomarkers. The review also evaluates the clinical application of liquid biopsy in major cancer types, including lung, breast, colorectal, prostate, and gastric cancers, emphasizing its significance not just in diagnosis but also in monitoring treatment response, tracking minimal residual disease, and understanding tumor heterogeneity. Despite its groundbreaking potential, challenges such as standardizing tests, low analyte levels in early-stage diseases, and the need for thorough clinical validation continue to present obstacles. This review concludes that liquid biopsy is set to become a vital component of precision oncology. Future initiatives must prioritize integrating multiple omics, conducting extensive prospective trials, and establishing standardized protocols to fully exploit its potential in advancing earlier cancer detection and personalized healthcare.