title: Human epidermal growth factor receptor 2 status of gastric cancer patients in Asia: results from a large, multicountry study.
abstract: OBJECTIVE
  Current estimates of the human epidermal growth factor receptor 2 (HER2)-positivity rate in gastric cancer vary widely in the literature, and there are limited data from countries in Asia. The primary aim of this study was to conduct a clinical audit of laboratories across seven countries in Asia to determine the incidence of HER2-positive gastric cancer in this region.
  
  
  METHODS
  Pathologists were asked to collect data on patient gender, age, cancer site, specimen type, tumor spread, type and grade, HER2 test results, including protein and/or gene copy enumeration, and final HER2 status on consecutive gastric cancer cases tested for HER2 in their laboratory over a 2-year period.
  
  
  RESULTS
  HER2 results from 5,301 gastric cancers were submitted by 50 laboratories. The overall HER2-positivity rate was 9.7% which, after the exclusion of China, increased to 18.1%. The rate between countries ranged from 0% to 23.1%, and from 0% to 50.0% between laboratories. An equivocal HER2 result was recorded in 19.5% of cases.
  
  
  CONCLUSIONS
  Despite the lack of centralized testing to confirm the accuracy of HER2 diagnoses, the incidence of HER2-positive gastric cancer observed here was comparable to that reported in the literature. Nevertheless, rates were highly variable between countries and laboratories, which suggests a lack of HER2 testing expertise in gastric cancer. Given that the mortality rates for gastric cancer in Eastern Asia are the highest in the world, efforts should focus on improving HER2 testing expertise in the region so that patients receive the appropriate treatment early in their disease.
authors.affiliation: Department of Tissue Pathology and Diagnostic Oncology, Pathology West, Westmead Breast Cancer Institute, Westmead Hospital, Western Sydney University and University of Sydney, Sydney, Australia.
authors.forename: Nirmala
authors.initials: N
authors.lastname: Pathmanathan
authors.affiliation: Harbin Medical University Cancer Hospital, Harbin, China.
authors.forename: Jing-Shu
authors.initials: JS
authors.lastname: Geng
authors.affiliation: The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
authors.forename: Wencai
authors.initials: W
authors.lastname: Li
authors.affiliation: Wuhan Union Hospital, Hubei, China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Nie
authors.affiliation: National Kidney and Transplant Institute, Quezon City, Philippines.
authors.forename: Januario
authors.initials: J
authors.lastname: Veloso
authors.affiliation: China Medical University Hospital, Taichung, Taiwan.
authors.forename: John
authors.initials: J
authors.lastname: Wang
authors.affiliation: McCloud Consulting Group Pty Ltd, Sydney, Australia.
authors.forename: Julie
authors.initials: J
authors.lastname: Hill
authors.affiliation: McCloud Consulting Group Pty Ltd, Sydney, Australia.
authors.forename: Philip
authors.initials: P
authors.lastname: Mccloud
authors.affiliation: Australian Clinical Labs, Norwest Private Hospital, Western Sydney University and University of Sydney, Sydney, Australia.
authors.forename: Michael
authors.initials: M
authors.lastname: Bilous
mesh_terms: D000328:Adult; D001208:Asia; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D008297:Male; D008875:Middle Aged; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000276:immunology*; D013274:Stomach Neoplasms / Q000276:immunology* / Q000473:pathology
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human
keywords: Asia; gastric cancer; human epidermal growth factor receptor 2