Figure 1.

Liquid biopsy potential for cancer monitoring. (A) Complementarity of tissue and liquid biopsies. (B) Overview of liquid biopsy biomarkers that represent the tumor molecular heterogeneity and immunologic phenotype. The primary tumor and metastatic sites release different cells and biomolecules in the bloodstream. Circulating tumor cells (CTCs; as single cells or clusters), circulating tumor DNA (ctDNA), extracellular vesicles (EVs), and tumor-educated platelets (TEPs) can be isolated from whole blood to obtain cancer genome, transcriptome, proteome, and secretome data in real time. Moreover, white blood cells (WBC) can give information on the immunity of the patient with cancer, mainly on their potential to eradicate cancer cells. All these biomarkers are complementary and can be used to build a precise index or an algorithm based on qualitative and quantitative data at different times during the disease course.