Liquid Biopsy in Cancer Monitoring: Beyond Circulating Tumor DNA
Keywords:
Liquid Biopsy, Neoplasms, Circulating Tumor DNA, Extracellular Vesicles, RNA, Proteomics, High-Throughput Nucleotide SequencingAbstract
Liquid biopsy has become a potent, least invasive way of detecting, monitoring, and treating cancer by studying cancer-causing biomarkers in body fluids. The circulating tumor DNA (ctDNA) has long been the foundation of the liquid biopsy as it has the capability of measuring tumor-specific genetic changes. New developments have made it possible to identify and characterize a wide range of circulating analytes, such as ctDNA, extracellular vesicles, circulating RNA, tumor-educated platelets, and circulating proteins and metabolites. These biomarkers are associated with tumor viability, transcriptional activity, metastatic potential, and metabolic reprogramming. Innovations in next-generation sequencing, microfluidics, proteomics, and single-cell analysis have led to the detection platforms of many multi-analytes being immensely sensitive and reliable. Integrative liquid biopsy platforms can help to assess the evolution and therapeutic resistance of tumors in a holistic manner through the integration of genomic, transcriptomic, and proteomic and cellular data. Moreover, data interpretation has also been improved with the implementation of artificial intelligence and machine learning, resulting in reliable classification of the disease, risks stratification, and predict the response to treatment. Although significant progress has been made, complications such as, variability in analysis, absence of standardized protocols, high cost of operation, and biological heterogeneity, restrict the extensive clinical implementation. Technological advancement and interdisciplinary cooperation will continue to intensify the role of liquid biopsy in achieving the possibility of early detection, real-time monitoring, and optimal cancer management.
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