Liquid biopsies in colorectal cancer screening and diagnosis
Colorectal cancer (CRC) remains a leading cause of global cancer mortality, underscoring the urgent need for effective early detection. Current screening methods, primarily colonoscopy, are limited by invasiveness and low population adherence, while traditional serological biomarkers lack sufficient sensitivity and specificity for reliable early-stage diagnosis. This review examines recent advances in liquid biopsy components as promising noninvasive biomarkers for CRC screening and diagnosis. Key circulating analytes are discussed, including circulating tumor cells, circulating tumor DNA, tumor-educated platelets, exosomes, and circulating RNAs. These markers collectively provide a systemic, real-time molecular profile of tumors, offering valuable information on tumor presence, stage, and biological characteristics beyond that achieved by traditional single-marker approaches. Integrating multiple biomarkers into diagnostic panels shows promise for significantly improving detection accuracy compared to conventional biomarkers like carcinoembryonic antigen. However, translating this potential into clinical practice faces substantial challenges, including the standardization of techniques, validation in large prospective cohorts, and demonstration of improved patient outcomes through interventional studies. Addressing these challenges is essential for realizing the transformative potential of liquid biopsies in personalized CRC management. By enabling earlier, less invasive, and more-accurate diagnosis, liquid biopsy represents a paradigm shift in screening that could ultimately reduce CRC mortality through timely intervention.