title: Discordance between original and central laboratories in ER and HER2 results in a diverse, population-based sample.
abstract: To investigate the discordance between original and central laboratories in estrogen receptor (ER) status, in tumors originally deemed to be ER-negative, and in HER2 status in a diverse population-based sample.
  
  
  
  In a follow-up study of 1785 women with Stage I-III breast cancer diagnosed between 2005 and 2007 in the Detroit and Los Angeles County SEER registry catchment areas, participants were asked to consent to reassessment of ER (in tumors originally deemed to be ER-negative) and HER2 status on archival tumor samples approximately four years after diagnosis. Blocks were centrally prepared and analyzed for ER and HER2 using standardized methods and the guidelines of the American Society of Clinical Oncology and the College of American Pathologists. Analyses determined the discordance between original and central laboratories.
  
  
  
  132 (31%) of those eligible for ER reassessment and 367 (21%) eligible for HER2 reassessment had archival blocks reassessed centrally. ER discordance was only 6%. HER2 discordance by immunohistochemistry (IHC) was 26%, but final HER2 results-employing FISH in tumors that were IHC 2+ at the central laboratory-were discordant in only 6%. Half of the original laboratories did not perform their own assays.
  
  
  
  Discordance between original and central laboratories in two large metropolitan areas was low in this population-based sample compared to previously reported patient samples. Centralization of testing for key pathology variables appears to be occurring in many hospitals. In addition, quality improvement efforts may have preceded the publication and dissemination of specialty society guidelines.
authors.affiliation: University of Michigan, 2800 Plymouth Rd., Building 16, 116W, Ann Arbor, MI, 48109, USA. jengrigg@umich.edu.
authors.forename: Jennifer J
authors.identifier: 0000-0002-1598-4562
authors.initials: JJ
authors.lastname: Griggs
authors.affiliation: Keck School of Medicine, University of Southern California, 2001 N. Soto St 318E, Los Angeles, CA, 90089, USA.
authors.forename: Ann S
authors.initials: AS
authors.lastname: Hamilton
authors.affiliation: Wayne State University School of Medicine, 320 E. Canfield, Detroit, MI, 48201, USA.
authors.forename: Kendra L
authors.initials: KL
authors.lastname: Schwartz
authors.affiliation: The Ohio State University, 2001 Polaris Parkway, Columbus, OH, 43240, USA.
authors.forename: Weiqiang
authors.initials: W
authors.lastname: Zhao
authors.affiliation: University of Michigan, 2800 Plymouth Rd., Building 16, 116W, Ann Arbor, MI, 48109, USA.
authors.forename: Paul H
authors.initials: PH
authors.lastname: Abrahamse
authors.affiliation: University of Michigan, 2800 Plymouth Rd., Building 16, 116W, Ann Arbor, MI, 48109, USA.
authors.forename: Dafydd G
authors.initials: DG
authors.lastname: Thomas
authors.affiliation: University of Michigan, 2800 Plymouth Rd., Building 16, 116W, Ann Arbor, MI, 48109, USA.
authors.forename: Julie M
authors.initials: JM
authors.lastname: Jorns
authors.affiliation: The Ohio State University, 2001 Polaris Parkway, Columbus, OH, 43240, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Jewell
authors.affiliation: Keck School of Medicine, University of Southern California, 2001 N. Soto St 318E, Los Angeles, CA, 90089, USA.
authors.forename: Maria E Sibug
authors.initials: ME
authors.lastname: Saber
authors.affiliation: Kaiser Permanente Southern California, Research & Evaluation, 100 S Los Robles, Pasadena, CA, 91101, USA.
authors.forename: Reina
authors.initials: R
authors.lastname: Haque
authors.affiliation: University of Michigan, 2800 Plymouth Rd., Building 16, 116W, Ann Arbor, MI, 48109, USA.
authors.forename: Steven J
authors.initials: SJ
authors.lastname: Katz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor; D001943:Breast Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000378:metabolism*; D064790:Clinical Laboratory Services / Q000592:standards*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods / Q000592:standards; D017404:In Situ Hybridization, Fluorescence / Q000379:methods / Q000592:standards; D008875:Middle Aged; D060787:Neoplasm Grading; D009367:Neoplasm Staging; D011159:Population Surveillance; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011960:Receptors, Estrogen / Q000235:genetics / Q000378:metabolism*; D015203:Reproducibility of Results; D018426:SEER Program; D055815:Young Adult
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen
keywords: Breast cancer; Estrogen receptor; HER2; Pathology; SEER registry