{"entity":{"id":"paper-tempero-ca19-9-lewis-antigens-cancer-res-1987","kind":"paper","name":"Relationship of carbohydrate antigen 19-9 and Lewis antigens in pancreatic cancer","aka":[],"tldr":"The 1987 study showing that people who lack the Lewis blood group antigens cannot make the CA 19-9 tumour marker, so in about one patient in ten a normal blood test says nothing about the cancer.","summary":"Tempero and colleagues studied 20 pancreatic cancer patients: Lewis a and b phenotype in saliva or on red cells, serum CA 19-9 by radioimmunoassay, and CA 19-9 and Lewis antigen expression in tumour tissue by immunoperoxidase. Patients who were Lewis a-negative b-negative failed to express CA 19-9 in tumour tissue and had normal or low serum levels (below 37 units per millilitre; P = 0.0011 versus Lewis-positive patients), whereas 88 percent of Lewis a-positive or b-positive patients had raised serum CA 19-9. The authors concluded that Lewis-negative patients cannot manufacture CA 19-9, and noted that Lewis a-positive patients unexpectedly expressed Lewis b antigen in tumour tissue.","asOf":"2026-09-24","links":[{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/3308077/"},{"label":"Europe PMC record","url":"https://europepmc.org/article/MED/3308077"}],"tags":["pancreatic-evidence"],"related":["paper-fahrmann-ca19-9-lead-time-gastroenterology-2021"],"cancers":["pancreatic"],"sections":[],"technologies":[],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["ca19-9","tumour-markers","lewis-negative"],"trials":[],"people":[],"bottlenecks":["b-biomarker-validation"],"keyPapers":[],"journals":["cancer-research"],"dependsOn":[],"notes":[],"journal":"Cancer Research","year":1987,"pmid":"3308077","authors":"Tempero MA, Uchida E, Takasaki H, et al.","paperType":"translational","findings":["Lewis a-negative b-negative patients did not express CA 19-9 in tumour or serum (P = 0.0011).","88 percent of Lewis-positive patients had serum CA 19-9 above 37 units per millilitre."],"whatItMeans":"The reason a normal CA 19-9 never rules pancreatic cancer out, why Lewis-negative patients need a different marker (CA 125, CEA or CA 19-9-independent panels), and a constraint on every blood-based detection idea on this page.","caveats":["Twenty patients, 1987 assays.","No DOI is indexed; the PubMed record is the anchor."],"participants":20},"route":"/key-papers/paper-tempero-ca19-9-lewis-antigens-cancer-res-1987/","neighbours":{"paper":[{"id":"paper-fahrmann-ca19-9-lead-time-gastroenterology-2021","kind":"paper","name":"Lead-Time Trajectory of CA19-9 as an Anchor Marker for Pancreatic Cancer Early Detection","route":"/key-papers/paper-fahrmann-ca19-9-lead-time-gastroenterology-2021/"}],"cancer":[{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"}],"term":[{"id":"ca19-9","kind":"term","name":"CA 19-9","route":"/terms/ca19-9/"},{"id":"lewis-negative","kind":"term","name":"Lewis-negative (Lewis antigen-negative, CA 19-9 non-secretor) status","route":"/terms/lewis-negative/"},{"id":"tumour-markers","kind":"term","name":"Tumour markers (CEA, LDH, chromogranin, thyroglobulin)","route":"/terms/tumour-markers/"}],"bottleneck":[{"id":"b-biomarker-validation","kind":"bottleneck","name":"Biomarkers are not validated or standardised","route":"/bottlenecks/b-biomarker-validation/"}],"journal":[{"id":"cancer-research","kind":"journal","name":"Cancer Research","route":"/journals/cancer-research/"}],"roadmap":[{"id":"pancreatic-roadmap","kind":"roadmap","name":"Pancreatic cancer roadmap: from Whipple's operation to gemcitabine, FOLFIRINOX, adjuvant chemotherapy, PARP inhibition, KRAS inhibition, vaccines and the surveillance question","route":"/roadmaps/pancreatic-roadmap/"}],"idea":[{"id":"idea-pdac-new-onset-diabetes-risk-score-pathway","kind":"idea","name":"Run the ENDPAC score on every new diabetes diagnosis after 50 and scan the high scorers","route":"/ideas/idea-pdac-new-onset-diabetes-risk-score-pathway/"}]}}