title: Human epidermal growth factor receptor 2 overexpression and amplification in endoscopic biopsies and resection specimens in esophageal and junctional adenocarcinoma.
abstract: Human epidermal growth factor receptor 2 (HER2) is overexpressed in a subset of esophageal adenocarcinomas. Frequently, biopsy material is used for evaluation of HER2 status. The aim of the study was to determine if HER2 expression in preoperative endoscopic biopsies is representative for the entire tumor. Preoperative endoscopic biopsies and matched resection specimens were collected from 75 patients who underwent esophagectomy for esophageal adenocarcinoma. Immunohistochemical staining (IHC) on HER2 and dual-color in situ hybridization (ISH) were performed. HER2 status was determined by following a clinical algorithm, first determining HER2 overexpression on immunohistochemistry and, when equivocal (2+), determining HER2 amplification on ISH. Seventy-one of 75 (95%) biopsies and 69/75 (92%) resection specimens could be analyzed due to technical failure. HER2 positivity was seen in 18/71 (25%) biopsies and in 15/69 (22%) resection specimens. Overall, HER2 status in the biopsy was concordant with HER2 status in the resection specimen in 94% of cases. Interobserver agreement on IHC scoring for all three observers was 83% in biopsies and 85% in resection specimens. HER2 positivity was detected in 22% of esophageal adenocarcinomas. Although interobserver agreement was moderate, HER2 status of a primary tumor can be reliably determined based on the endoscopically obtained pretreatment biopsy.
authors.affiliation: Department of Surgery, Erasmus MC, University Medical Centre Rotterdam, Rotterdam, The Netherlands.
authors.forename: P
authors.initials: P
authors.lastname: van Hagen
authors.forename: K
authors.initials: K
authors.lastname: Biermann
authors.forename: J E
authors.initials: JE
authors.lastname: Boers
authors.forename: O
authors.initials: O
authors.lastname: Stoss
authors.forename: H F
authors.initials: HF
authors.lastname: Sleddens
authors.forename: J J B
authors.initials: JJ
authors.lastname: van Lanschot
authors.forename: W N M
authors.initials: WN
authors.lastname: Dinjens
authors.forename: J
authors.initials: J
authors.lastname: Rueschoff
authors.forename: B P L
authors.initials: BP
authors.lastname: Wijnhoven
mesh_terms: D000230:Adenocarcinoma / Q000378:metabolism* / Q000601:surgery; D000368:Aged; D001706:Biopsy; D004938:Esophageal Neoplasms / Q000378:metabolism* / Q000601:surgery; D004943:Esophagogastric Junction / Q000378:metabolism* / Q000601:surgery; D004945:Esophagoscopy; D005260:Female; D005784:Gene Amplification; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism*; D015203:Reproducibility of Results; D013194:Staining and Labeling / Q000379:methods
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: HER2; esophageal adenocarcinoma; protein expression