Table 1.

Characteristics of circulating biomarkers and tumor biopsy.

Circulating Biomarkers and Liquid Biopsy	Tumor Biopsy
Material derived from cancer detectable in bloodstream, urine, or peritoneal fluid	Material obtained from a sampling of tissue lesion
Non-invasive procedure	High invasive procedure
Real-time follow up	Impracticable for real-time follow up
Quick and easily repeatable procedure for obtaining the samples	Difficult to repeat and depend on the correctness of the procedure
No surgical complication or pain	Risk of surgical complication and pain
Lack of well-defined practice rules and standardizing protocols	Clinically validated and standard for histologic diagnosis
Less cost (with some exceptions)	High cost
Assessment of tumor heterogeneity in different phases of the disease	Failure to reflect tumor heterogeneity
Low concentrations and easily degradable material	Higher concentration and fixed material
Less specificity	Higher specificity
Specialized laboratory	Histology laboratory