Abstract

Liquid biopsies, such as tumor-relevant proteins, miRNAs, circulating tumour cells (CTC) and cell-free DNA (cfDNA), have all been shown to have promising potential to be used as cancer biomarkers. However, the sensitivity and specificity of these biomarkers are currently insufficient, prohibiting their widespread application in clinical practice. Circulating tumour DNA (ctDNA) has received a lot of attention in recent years as a potential diagnostic and prognostic tool. Since tumours release genetic material, (i. e. ctDNA) into the bloodstream before they are apparent on imaging or cause symptoms, thus, ctDNA is one of the most promising liquid biopsy biomarkers for early diagnosis, prognosis, and treatment monitoring of patients with cancer. Accordingly, extensive preclinical and clinical research support that ctDNA has the potential to be considered a novel tool in early cancer diagnosis and prognosis. Also, ctDNA analysis can reliably predict tumour growth and treatment efficacy, as well as can aid in targeted therapy. Herein, this chapter will discuss the clinical significance of ctDNA in the management of patients with cancer as a potential liquid biopsy biomarker.