Re-biopsy		Liquid biopsy
Advantages	Disadvantages	Advantages	Disadvantages
High sensitivity and specificity	Invasive and limited use in patients with poor performance status and inaccessible tumor sites	Less invasive and can be used in patients with poor performance status and inaccessible tumor sites	Risk of false-positive results are more
Histological transformations and subtyping are possible	Turnaround time is more	Turnaround time is less compared to tissue biopsy	Somatic mutations in the plasma due to clonal hematopoiesis hamper the result
Confirmation on metastases/relapse	Complete genomic alterations are not visible due to tumor heterogeneity	Sources of DNA, such as blood, serum, plasma, saliva, or urine can be analyzed for molecular alterations	Test sensitivity challenges still exist due to the relatively low level of circulating tumor cells or DNA
Tumor microenvironment can be checked	Tissue biopsy from a metastatic site may not explain the real nature of the primary tumor	Reported > 90% concordance with tissue re-biopsy	Histologic transformations are difficult to find
Immunohistochemistry is cheaper than molecular techniques in assessing biomarkers such as PDL-1	Preservation methods such as formalin fixation can result in false-positive results in molecular assays	It can be easily repeated if needed and can be used as often as necessary to monitor the patient’s progress	Very expensive as compared to Immunohistochemistry
		It can be used to estimate the risk for metastatic relapse or metastatic progression	Very expensive as compared to Immunohistochemistry