# OnCo record ctdna-tumour-fraction (biomarker). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)". Whole corpus: https://onco.cc/api/v1/onco.nt
@prefix schema: <https://schema.org/> .
@prefix onco: <https://onco.cc/ns#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .

<https://onco.cc/biomarkers/ctdna-tumour-fraction/>
  a schema:MedicalTest ;
  onco:kind "biomarker" ;
  schema:identifier "ctdna-tumour-fraction" ;
  schema:name "Circulating tumour DNA fraction (and what a negative plasma result means)"@en ;
  schema:alternateName "ctDNA fraction"@en, "circulating tumour DNA fraction"@en, "tumour fraction"@en, "ctDNA%"@en, "cfDNA tumour content"@en, "plasma tumour fraction"@en ;
  schema:description "How much of the DNA floating in a blood sample came from the cancer. Above a few per cent, a plasma test finds what a biopsy would find; below it, a negative result means the test could not see, not that there is nothing there."@en ;
  schema:url <https://onco.cc/biomarkers/ctdna-tumour-fraction/> ;
  schema:dateModified "2026-09-25"^^xsd:date ;
  schema:citation <https://doi.org/10.1093/jnci/djx118>, <https://doi.org/10.1158/1078-0432.CCR-20-4805>, <https://doi.org/10.1001/jamaoncol.2020.5161> ;
  onco:tag "biomarker", "prostate" ;
  onco:related <https://onco.cc/biomarkers/hrr-gene-mutation/>, <https://onco.cc/biomarkers/ar-amplification/>, <https://onco.cc/biomarkers/ctdna-mrd-positive/> ;
  onco:cancers <https://onco.cc/cancers/prostate/>, <https://onco.cc/cancers/prostate-mcrpc/> ;
  onco:technologies <https://onco.cc/technologies/liquid-biopsy/>, <https://onco.cc/technologies/cgp/> ;
  onco:targets <https://onco.cc/targets/brca/>, <https://onco.cc/targets/androgen-receptor/>, <https://onco.cc/targets/atm/> ;
  onco:pathways <https://onco.cc/pathways/clonal-evolution/>, <https://onco.cc/pathways/homologous-recombination-repair/>, <https://onco.cc/pathways/clonal-haematopoiesis/> ;
  onco:terms <https://onco.cc/terms/ctdna/>, <https://onco.cc/terms/cfdna/>, <https://onco.cc/terms/germline-vs-somatic/>, <https://onco.cc/terms/vus/>, <https://onco.cc/terms/biopsy/> ;
  onco:keyPapers <https://onco.cc/key-papers/paper-wyatt-ctdna-tissue-concordance-mcrpc-jnci-2017/>, <https://onco.cc/key-papers/paper-tukachinsky-ctdna-3334-advanced-prostate-ccr-2021/>, <https://onco.cc/key-papers/paper-jensen-clonal-haematopoiesis-cfdna-interference-prostate-jama-oncol-2021/>, <https://onco.cc/key-papers/paper-annala-ctdna-resistance-abiraterone-enzalutamide-cancer-discov-2018/> .