Table 3.

Advantages and Disadvantages of the different liquid biopsy sources in relation to CNVs.

	ctDNA	CTC	Extracellular Vesicles
Advantages
Detection of tumor heterogeneity	√	√	√
Offers RNA- and DNA-based measurements		√	√
Use of standardized methodology exemplified by CE-IVD platform for enumeration and capturing and ctDNA mutation and methylation assays	√	√
Can monitor disease progression and relapse	√		√
Disadvantages
Present in low numbers—large amount of sample required	√	√
Patient-derived material is specific to a disease stage exemplified by CTC in metastatic disease		√
Extensive analytic and clinical validity required	√		√