Potentialities and challenges of liquid biopsy in clinical cancer management

Assessment of biomarkers through liquid biopsy, accompanied by low invasiveness, provides a more comprehensive analysis of the genetic profile of tumors, a deeper understanding of cancer mechanisms, the capacity for repeated testing over time, a short processing time, ease of obtaining, and economic benefits, making it easier to monitor diseases compared to tissue biopsy. Circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), exosomes, non-coding RNAs, and metabolites provide precise and timely strategies for managing cancer patients. The main challenges are the low concentration of analytes isolated from liquid biopsies, the development of assays with both high sensitivity and specificity, and the lack of clear and comprehensive guidelines for assays, which further complicate the standardization process. Combined detection, including both CTCs and ctDNA assessment in circular bodies, provides valuable information at different stages of the tumor, despite the heterogeneity of tumor cells, for prognosis, dynamic monitoring, and mutation detection. In addition, the combination of biofluid biomarkers and artificial intelligence can enhance the accuracy and efficiency of liquid biopsy, improve real-time monitoring of tumor procedures and treatment responses, and provide precision medicine. This review examines the challenges in standardizing biofluid assays and explores potential solutions to achieve more consistent clinical outcomes.