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.
Keywords: Cancer biomarkers, Circulating tumour DNA (ctDNA), Early cancer detection, Liquid biopsy, Prognosis, Risk of relapse, Treatment efficacy.
