TABLE 1.

Advantages and caveats of comprehensive genomic profiling (CGP) assay using plasma and tissue specimens\

	Advantages	Important points
Plasma CGP	‐Easy to collect specimens and to obtain information on genetic abnormalities of the tumor at the time of collection ‐Short time to obtain results	‐If the tumor volume is insufficient, alterations might not be detectable ‐False‐negative rates for plasma CGP are often higher than those for tissue CGP ‐Increased false‐positives because of CHIP in elderly patients ‐Copy number changes and gene fusions may be difficult to assess
Tissue CGP	‐Direct assessment of genetic abnormalities in tumor cells	‐Burden to patient and risk of complications at biopsy site ‐Longer turnaround time ‐Higher false‐negative rate when tumor cell percentage is low ‐Past samples may not reflect the genetic abnormalities in the tumor cells at present ‐Specimens obtained more than 3‐5 years previously will have deteriorated and will not be suitable for CGP assa