# OnCo record lewis-negative (term). 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/terms/lewis-negative/>
  a schema:DefinedTerm ;
  onco:kind "term" ;
  schema:identifier "lewis-negative" ;
  schema:name "Lewis-negative (Lewis antigen-negative, CA 19-9 non-secretor) status"@en ;
  schema:alternateName "Lewis antigen-negative"@en, "Lewis negative phenotype"@en, "CA 19-9 non-secretor"@en, "FUT3 null"@en, "Lewis blood group negative"@en, "Le(a-b-)"@en ;
  schema:description "About one person in ten to twenty cannot make the sugar that the CA 19-9 blood test measures, because they lack a working copy of the Lewis blood-group gene. In these Lewis-negative people the test stays low however large the cancer, so a normal CA 19-9 does not rule pancreatic cancer out, and their cancers appear to behave more aggressively."@en ;
  schema:url <https://onco.cc/terms/lewis-negative/> ;
  schema:dateModified "2026-09-24"^^xsd:date ;
  schema:sameAs <https://en.wikipedia.org/wiki/CA19-9> ;
  schema:citation <https://doi.org/10.3978/j.issn.2078-6891.2011.021>, <https://doi.org/10.1016/j.pan.2018.08.003>, <https://doi.org/10.3892/ijo.2020.4989> ;
  onco:tag "gi", "pancreatic" ;
  onco:cancers <https://onco.cc/cancers/pancreatic/>, <https://onco.cc/cancers/metastatic-pdac/>, <https://onco.cc/cancers/cholangiocarcinoma/> ;
  onco:technologies <https://onco.cc/technologies/liquid-biopsy/> ;
  onco:terms <https://onco.cc/terms/ca19-9/>, <https://onco.cc/terms/ppv/> .