title: HER2 expression status in diverse cancers: review of results from 37,992 patients.
abstract: Human epidermal growth factor receptor 2 (HER2) amplification/overexpression is an effective therapeutic target in breast and gastric cancer. Although HER2 positivity has been reported in other malignancies, previous studies generally focused on one cancer type, making it challenging to compare HER2 positivity across studies/malignancies. Herein, we examined 37,992 patient samples for HER2 expression (+/- amplification) in a single laboratory. All 37,992 patients were tested by immunohistochemistry (IHC); 21,642 of them were also examined for HER2 amplification with either fluorescent in situ hybridization (FISH) (11,670 patients) or chromogenic in situ hybridization (CISH) (9,972 patients); 18,262 patients had tumors other than breast or gastric cancer. All tissues were analyzed in a Clinical Laboratory Improvement Amendments (CLIA) laboratory (Caris Life Sciences) at the request of referring physicians. HER2 protein overexpression was found in 2.7 % of samples. Over-expressed HER2 was detected predominantly in malignancies of epithelial origin; for cancers derived from mesenchyme, neuroendocrine tissue, central nervous system, and kidney, HER2 expression and amplification were remarkably rare or non-existent. Bladder carcinomas, gallbladder, extrahepatic cholangiocarcinomas, cervical, uterine, and testicular cancers showed HER2 positivity rates of 12.4, 9.8, 6.3, 3.9, 3.0, and 2.4 %, respectively. HER2 overexpression and/or amplification is frequently found across tumor types. These observations may have significant therapeutic implications in cancers not traditionally thought to benefit from anti-HER2 therapies.
authors.affiliation: Center for Personalized Cancer Therapy, UC San Diego Moores Cancer Center, 3855 Health Sciences Drive, MC #0658, La Jolla, CA, 92093-0658, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Yan
authors.forename: Maria
authors.initials: M
authors.lastname: Schwaederle
authors.forename: David
authors.initials: D
authors.lastname: Arguello
authors.forename: Sherri Z
authors.initials: SZ
authors.lastname: Millis
authors.forename: Zoran
authors.initials: Z
authors.lastname: Gatalica
authors.forename: Razelle
authors.initials: R
authors.lastname: Kurzrock
mesh_terms: D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization / Q000379:methods*; D017404:In Situ Hybridization, Fluorescence; D009369:Neoplasms / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000096:biosynthesis / Q000235:genetics*
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human