Current Status of Liquid Biopsy Biomarkers in Cancer

Liquid biopsy is a non-invasive diagnostic tool in cancer management, which offers real-time molecular information about tumor biology. The analysis of circulating biomarkers, including circulating tumor cells (CTCs), cell-free DNA (cfDNA), circulating tumor DNA (ctDNA), exosomes, and microRNAs, provides valuable information about tumor heterogeneity, clonal evolution, and treatment response. These biomarkers enable early cancer detection, disease monitoring, and therapeutic decision-making while overcoming the limitations of traditional tissue biopsies. CTCs serve as direct representatives of tumor cells in circulation, while cfDNA and ctDNA analysis reveals genetic alterations and tumor burden. Exosomes and microRNAs play crucial roles in intercellular communication and disease progression. The clinical implementation of liquid biopsy has shown promising results in various cancer types, particularly in lung, breast, colorectal, and prostate cancers. Several challenges still continue to barricade the use of liquid biopsy, which includes standardization of isolation techniques, optimization of detection methods, and interpretation of results. The usage of multiple biomarker analyses and advanced molecular techniques has improved diagnostic accuracy and prognostic value.