{"entity":{"id":"paper-hiraoka-her2-status-biliary-hum-pathol-2020","kind":"paper","name":"Details of human epidermal growth factor receptor 2 status in 454 cases of biliary tract cancer","aka":[],"tldr":"Testing 454 resected biliary cancers with the stomach cancer HER2 rules, nearly one in three gallbladder cancers was HER2-positive, far more than bile duct cancers inside the liver, but staining was patchy in most positive tumours.","summary":"HER2 protein expression by immunohistochemistry, HER2 gene amplification by fluorescence in situ hybridisation and both simultaneously by gene-protein assay were examined in 454 surgically resected biliary tract cancers: 110 intrahepatic cholangiocarcinomas, 67 perihilar and 119 distal extrahepatic cholangiocarcinomas, 80 gallbladder carcinomas and 79 ampullary carcinomas. HER2 status was assessed according to the guidelines for HER2 testing in gastro-oesophageal adenocarcinoma.\n\nHER2-positive status was detected in 14.5% of biliary tract cancers: 3.7% of intrahepatic, 3.0% of perihilar and 18.5% of distal cholangiocarcinomas, 31.3% of gallbladder carcinomas and 16.4% of ampullary carcinomas. HER2 positivity tended to correlate with low histological grade. HER2 heterogeneity was common and highly frequent (83%) in positive cases, and reduced HER2 expression in the deeper invasive areas with simultaneous dedifferentiation was frequently observed.","asOf":"2026-09-24","links":[{"label":"Hiraoka et al., Hum Pathol 2020: HER2 status in 454 biliary tract cancers","url":"https://doi.org/10.1016/j.humpath.2020.08.006"},{"label":"PubMed","url":"https://pubmed.ncbi.nlm.nih.gov/32891647/"}],"tags":[],"related":[],"cancers":["gallbladder","cholangiocarcinoma","ampullary"],"sections":[],"technologies":[],"targets":["her2"],"drugs":[],"companies":[],"institutions":["ncc-japan"],"pathways":[],"terms":["ihc","fish","her2-testing-in-biliary-cancer"],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"journal":"Human Pathology","year":2020,"doi":"10.1016/j.humpath.2020.08.006","pmid":"32891647","authors":"Hiraoka N, Nitta H, Ohba A, et al.","paperType":"observational","findings":["HER2-positive in 31.3% of 80 gallbladder carcinomas versus 3.7% intrahepatic, 3.0% perihilar, 18.5% distal and 16.4% ampullary.","Heterogeneous HER2 expression in 83% of positive cases, with loss in deeper dedifferentiated areas.","Gastro-oesophageal scoring guideline applied to whole resection specimens."],"whatItMeans":"The highest gallbladder HER2 rate in the literature comes from whole resected tumours scored generously; biopsy-based trial screening finds fewer. Heterogeneity is the practical warning for pathologists and for why HER2-directed drugs do not work in every positive tumour.","caveats":["Resected Japanese patients; advanced disease tested on biopsies may score lower.","Gastric scoring is more permissive than breast scoring."],"changedPractice":false,"participants":454},"route":"/key-papers/paper-hiraoka-her2-status-biliary-hum-pathol-2020/","neighbours":{"cancer":[{"id":"ampullary","kind":"cancer","name":"Ampullary cancer (ampulla of Vater)","route":"/cancers/ampullary/"},{"id":"cholangiocarcinoma","kind":"cancer","name":"Biliary tract cancer (cholangiocarcinoma)","route":"/cancers/cholangiocarcinoma/"},{"id":"gallbladder","kind":"cancer","name":"Gallbladder cancer","route":"/cancers/gallbladder/"}],"target":[{"id":"her2","kind":"target","name":"HER2","route":"/targets/her2/"}],"institution":[{"id":"ncc-japan","kind":"institution","name":"National Cancer Center Hospital","route":"/institutions/ncc-japan/"}],"term":[{"id":"fish","kind":"term","name":"FISH / ISH (in situ hybridisation)","route":"/terms/fish/"},{"id":"her2-testing-in-biliary-cancer","kind":"term","name":"HER2 testing in biliary tract cancer (IHC, ISH and NGS)","route":"/terms/her2-testing-in-biliary-cancer/"},{"id":"ihc","kind":"term","name":"Immunohistochemistry (IHC)","route":"/terms/ihc/"}],"biomarker":[{"id":"her2-ihc-3-plus","kind":"biomarker","name":"HER2 IHC 3+ (HER2-positive by immunohistochemistry)","route":"/biomarkers/her2-ihc-3-plus/"}]}}