{"entity":{"id":"paper-sorlie-repeated-observation-subtypes-brca1-basal-pnas-2003","kind":"paper","name":"Repeated observation of breast tumor subtypes in independent gene expression data sets","aka":[],"tldr":"The 2003 paper that found the same breast cancer subtypes in other laboratories' data and showed that tumours from women with an inherited BRCA1 fault fall into the basal-like group, linking hereditary and triple-negative disease.","summary":"Sørlie, Tibshirani, Parker, Hastie and colleagues analysed 115 malignant breast tumours by hierarchical clustering on 534 intrinsic genes, selected for similar expression between paired samples from the same tumour taken 15 weeks apart during neoadjuvant treatment. The tumours subdivided into one basal-like, one ERBB2-overexpressing, two luminal-like and one normal breast tissue-like subgroup. Cluster analysis of two published independent data sets from different laboratories uncovered some of the same subtypes, and in the set with time to distant metastasis the subtypes differed significantly. Including tumours from BRCA1 carriers showed that this genotype predisposes to the basal tumour subtype.","asOf":"2026-09-24","links":[{"label":"Proc Natl Acad Sci 2003","url":"https://doi.org/10.1073/pnas.0932692100"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/12829800/"}],"tags":["tnbc-evidence"],"related":["paper-foulkes-brca1-basal-phenotype-jnci-2003"],"cancers":["tnbc"],"sections":[],"technologies":[],"targets":["brca"],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":["pam50","germline-testing"],"trials":[],"people":["charles-perou"],"bottlenecks":[],"keyPapers":[],"journals":["pnas"],"dependsOn":[],"notes":[],"journal":"Proceedings of the National Academy of Sciences","year":2003,"doi":"10.1073/pnas.0932692100","pmid":"12829800","authors":"Sørlie T, Tibshirani R, Parker J, et al.","paperType":"translational","findings":["115 tumours on 534 intrinsic genes: basal-like, ERBB2-overexpressing, two luminal-like and normal-like subgroups reproduced in two independent data sets.","BRCA1 carrier tumours fell into the basal subtype."],"whatItMeans":"The molecular bridge between germline BRCA1 and triple-negative breast cancer; it is why every triple-negative patient under 60 is now offered germline testing and why PARP inhibitors were tried in this disease first.","caveats":["Small BRCA1 group.","Independent data sets reproduced some, not all, subtypes."],"changedPractice":true,"participants":115},"route":"/key-papers/paper-sorlie-repeated-observation-subtypes-brca1-basal-pnas-2003/","neighbours":{"paper":[{"id":"paper-foulkes-brca1-basal-phenotype-jnci-2003","kind":"paper","name":"Germline BRCA1 mutations and a basal epithelial phenotype in breast cancer","route":"/key-papers/paper-foulkes-brca1-basal-phenotype-jnci-2003/"},{"id":"paper-perou-molecular-portraits-breast-tumours-nature-2000","kind":"paper","name":"Molecular portraits of human breast tumours","route":"/key-papers/paper-perou-molecular-portraits-breast-tumours-nature-2000/"}],"cancer":[{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"target":[{"id":"brca","kind":"target","name":"BRCA1 / BRCA2 (HRD)","route":"/targets/brca/"}],"term":[{"id":"pam50","kind":"term","name":"PAM50 / intrinsic subtypes","route":"/terms/pam50/"}],"technology":[{"id":"germline-testing","kind":"technology","name":"Germline (hereditary) testing","route":"/technologies/germline-testing/"}],"person":[{"id":"charles-perou","kind":"person","name":"Charles M. Perou","route":"/people/charles-perou/"}],"journal":[{"id":"pnas","kind":"journal","name":"Proceedings of the National Academy of Sciences","route":"/journals/pnas/"}],"roadmap":[{"id":"tnbc-roadmap","kind":"roadmap","name":"Triple-negative breast cancer roadmap: from a remainder defined by three negative tests to immunotherapy, antibody-drug conjugates and the residual disease problem","route":"/roadmaps/tnbc-roadmap/"}]}}