{"entity":{"id":"paper-fiala-ctdna-early-detection-bmc-med-2018","kind":"paper","name":"Utility of circulating tumor DNA in cancer diagnostics with emphasis on early detection","aka":[],"tldr":"A review that works out how many genome copies a blood sample holds, and why very small tumour fractions run out of molecules to find.","summary":"A review of circulating tumour DNA in diagnostics. Its full text states that most studies cite cell-free DNA in normal individuals at 1 to 10 ng per mL (average 5 ng per mL), that 5 ng of DNA equates to approximately 1,500 genomes, and that when the tumour fraction falls below 0.01 per cent a 10 mL blood draw (4 mL of plasma) will likely not contain a single cancer genome at a given locus, so detection becomes impossible through sampling error alone.","asOf":"2026-11-04","links":[{"label":"Fiala and Diamandis, BMC Med 2018","url":"https://doi.org/10.1186/s12916-018-1157-9"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/30285732/"}],"tags":[],"related":[],"cancers":[],"sections":["diagnostics"],"technologies":["liquid-biopsy"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["cfdna","ctdna"],"trials":[],"people":[],"bottlenecks":["b-subclone-attribution-residual-disease"],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"journal":"BMC Medicine","year":2018,"doi":"10.1186/s12916-018-1157-9","pmid":"30285732","authors":"Fiala C, Diamandis EP","paperType":"review","findings":["Cell-free DNA 1 to 10 ng/mL, average 5 ng/mL.","5 ng of DNA is approximately 1,500 genomes."],"whatItMeans":"The number of molecules in the tube, not the sequencer, sets the floor for any single-locus blood test; multi-locus tests escape it only by adding sites together.","caveats":["The argument is for a single locus in screening; residual disease tests track many loci."]},"route":"/key-papers/paper-fiala-ctdna-early-detection-bmc-med-2018/","neighbours":{"section":[{"id":"diagnostics","kind":"section","name":"Diagnostics & Biomarkers","route":"/fronts/diagnostics/"}],"technology":[{"id":"liquid-biopsy","kind":"technology","name":"Liquid biopsy (ctDNA)","route":"/technologies/liquid-biopsy/"}],"term":[{"id":"cfdna","kind":"term","name":"Cell-free DNA (cfDNA)","route":"/terms/cfdna/"},{"id":"ctdna","kind":"term","name":"Circulating tumour DNA (ctDNA)","route":"/terms/ctdna/"}],"bottleneck":[{"id":"b-subclone-attribution-residual-disease","kind":"bottleneck","name":"Naming which clone or phenotype is left after treatment","route":"/bottlenecks/b-subclone-attribution-residual-disease/"}]}}