{"entity":{"id":"paper-asco-cap-er-pr-testing-guideline-jco-2010","kind":"paper","name":"American Society of Clinical Oncology/College Of American Pathologists guideline recommendations for immunohistochemical testing of estrogen and progesterone receptors in breast cancer","aka":[],"tldr":"The 2010 rule that fixed the line between hormone receptor-positive and negative breast cancer at 1 percent of stained tumour nuclei, after finding that up to a fifth of receptor tests worldwide might be wrong; it is the threshold that defines triple-negative disease.","summary":"ASCO and College of American Pathologists guideline by Hammond, Hayes, Dowsett, Allred and colleagues, developed with Cancer Care Ontario from a systematic review. Up to 20 percent of immunohistochemical oestrogen and progesterone receptor determinations worldwide may be inaccurate, mostly through variation in pre-analytic handling, positivity thresholds and interpretation. The panel recommends that receptor status be determined on all invasive breast cancers and recurrences, proposes a testing algorithm with specified elements to reduce assay variation, and recommends that assays be considered positive if at least 1 percent of tumour nuclei stain in the presence of expected internal and external control reactivity. The absence of endocrine therapy benefit in receptor-negative disease has been confirmed in large overviews of randomised trials.","asOf":"2026-09-24","links":[{"label":"J Clin Oncol 2010","url":"https://doi.org/10.1200/JCO.2009.25.6529"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/20404251/"}],"tags":["tnbc-evidence"],"related":[],"cancers":["tnbc","breast-hr-positive"],"sections":[],"technologies":["digital-pathology-ai"],"targets":[],"drugs":[],"companies":[],"institutions":["asco"],"pathways":[],"terms":["ihc"],"trials":[],"people":[],"bottlenecks":["b-biomarker-validation"],"keyPapers":[],"journals":["jco"],"dependsOn":[],"notes":[],"journal":"Journal of Clinical Oncology","year":2010,"doi":"10.1200/JCO.2009.25.6529","pmid":"20404251","authors":"Hammond ME, Hayes DF, Dowsett M, et al.","paperType":"guideline","findings":["Up to 20 percent of immunohistochemical oestrogen and progesterone receptor determinations worldwide may be inaccurate.","Positive defined as at least 1 percent of tumour nuclei staining with expected control reactivity."],"whatItMeans":"Triple-negative is a laboratory definition; this guideline wrote the oestrogen and progesterone half of it, and the 1 to 10 percent low-positive band it created is still argued over.","caveats":["Immunohistochemistry thresholds are conventions; tumours with 1 to 10 percent staining behave more like receptor-negative disease in several series.","Predates the HER2-low and HER2-ultralow categories."],"changedPractice":true},"route":"/key-papers/paper-asco-cap-er-pr-testing-guideline-jco-2010/","neighbours":{"cancer":[{"id":"breast-hr-positive","kind":"cancer","name":"HR-positive / HER2-negative breast cancer","route":"/cancers/breast-hr-positive/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"technology":[{"id":"digital-pathology-ai","kind":"technology","name":"Digital pathology & AI","route":"/technologies/digital-pathology-ai/"}],"institution":[{"id":"asco","kind":"institution","name":"American Society of Clinical Oncology (ASCO)","route":"/institutions/asco/"}],"term":[{"id":"ihc","kind":"term","name":"Immunohistochemistry (IHC)","route":"/terms/ihc/"}],"bottleneck":[{"id":"b-biomarker-validation","kind":"bottleneck","name":"Biomarkers are not validated or standardised","route":"/bottlenecks/b-biomarker-validation/"}],"journal":[{"id":"jco","kind":"journal","name":"Journal of Clinical Oncology","route":"/journals/jco/"}],"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/"}],"paper":[{"id":"paper-slamon-her2-amplification-science-1987","kind":"paper","name":"Slamon 1987: HER2 gene amplification marks an aggressive form of breast cancer","route":"/key-papers/paper-slamon-her2-amplification-science-1987/"}]}}