Background: The field of liquid biopsies in oncology is rapidly expanding, with the application of cell-free circulating tumour DNA (ctDNA) showing promise in this era of precision medicine. Compared with traditional clinical and radiographic tumour monitoring methods, the analysis of ctDNA provides a minimally-invasive and technically feasible approach to assess temporal and spatial molecular evolutions of the tumour landscape. The constantly advancing technological platforms available for ctDNA extraction and analysis allow greater analytical sensitivities than ever before. The potential translational impact of ctDNA as a blood-based biomarker for the identification, characterization and monitoring of cancer has been demonstrated in numerous proof-of-concept studies, with ctDNA analysis beginning to be applied clinically across multiple facets of oncology.
Conclusions: In this review we discuss the biology, recent advancements, technical considerations and clinical implications of ctDNA in the context of cancer, and highlight important challenges and future directions for the integration of ctDNA into standardised patient care.
Keywords: Cell-free DNA; Circulating tumour DNA; cancer; liquid biopsy.