Application of Liquid Biopsies in Cancer Targeted Therapy

As a growing body of evidence demonstrates intertumoral and intratumoral heterogeneity and clonal evolution, both during carcinogenesis and also throughout treatment resulting in acquired drug resistance, the utility of blood‐based assays or “liquid biopsies” is becoming increasingly recognized in clinical practice and trial design. “Liquid biopsies” provide a less invasive approach to the current gold standard of interrogating tumors by tissue biopsies, which are frequently unfeasible, associated with morbidity, and cannot be performed as often.