Table 2.

Recommendation for a structured report

Clinical Data	- cancer diagnosis - disease stage - treatment at time of acquisition
Timing	- data (dd/mm) and time (hh/mm) of blood sample - data (dd/mm) and time (hh/mm) of plasma separation
Tubes used	- K2/K3EDTA-containing tubes - specialized blood collection tubes containing preservative agent
Result	- variants detected related to the clinical request - VAF for each variants detected - if a variant is not detected should be reported as “non-informative” or “not detected” rather than “negative”
Potential germline variants	Potential pathogenic germline variants in genes associated with heritable cancer predisposition should be flagged with an alert for the clinician
Variants potentially associated with CHIP	Variant identified in ctDNA assay is assumed to be present in the tumour but could be derived from leukocytes
Variant allele fractions for quantitative assays	Variant type and/or genomic features detected by assay SNVs, small insertions/deletions, amplifications, copy number losses, gene fusions, MSI, TMB and LOH
Technology used for analysis	- Q-PCR - dd-PCR - Mass Spettrometry - NSG
Kits used for the analysis	IVD or IVD-R certificated kits should be used
Limit of detection	In cases where input plasma DNA is limiting, a warning should be inserted in the report
Assay limitations	ctDNA results have an amount of discordance with tumour testing. The report should communicate this potential discordance