title: Diagnostic evaluation of HER-2 as a molecular target: an assessment of accuracy and reproducibility of laboratory testing in large, prospective, randomized clinical trials.
abstract: OBJECTIVE
  To critically assess the accuracy and reproducibility of human epidermal growth factor receptor type 2 (HER-2) testing in outside/local community-based hospitals versus two centralized reference laboratories and its effect on selection of women for trastuzumab (Herceptin)-based clinical trials.
  
  
  METHODS
  Breast cancer specimens from 2,600 women were prospectively evaluated by fluorescence in situ hybridization (FISH) for entry into Breast Cancer International Research Group (BCIRG) clinical trials for HER-2-directed therapies.
  
  
  RESULTS
  HER-2 gene amplification by FISH was observed in 657 of the 2,502 (26%) breast cancers successfully analyzed. Among 2,243 breast cancers with central laboratory immunohistochemistry (10H8-IHC) analysis, 504 (22.54%) showed overexpression (2+ or 3+). Outside/local laboratories assessed HER-2 status by immunohistochemistry in 1,536 of these cases and by FISH in 131 cases. Overall, the HER-2 alteration status determined by outside/local immunohistochemistry showed a 79% agreement rate [kappa statistic, 0.56; 95% confidence interval (95% CI), 0.52-0.60], with FISH done by the central laboratories. The agreement rate comparing BCIRG central laboratory 10H8-IHC and outside/local laboratory immunohistochemistry was 77.5% (kappa statistic, 0.51; 95% CI, 0.46-0.55). Finally, HER-2 status, determined by unspecified FISH assay methods at outside/local laboratories, showed a 92% agreement rate (kappa statistic, 0.83; 95% CI, 0.73-0.93), with FISH done at the BCIRG central laboratories.
  
  
  CONCLUSIONS
  Compared with the HER-2 status determined at centralized BCIRG reference laboratories, these results indicate superiority of FISH to accurately and reproducibly assess tumors for the HER-2 alteration at outside/local laboratories for entry to clinical trials.
authors.affiliation: Women's Cancers Program, Department of Pathology, Norris Comprehensive Cancer Center, University of Southern California Keck School of Medicine, Los Angeles, CA 89195, USA.
authors.forename: Michael F
authors.initials: MF
authors.lastname: Press
authors.forename: Guido
authors.initials: G
authors.lastname: Sauter
authors.forename: Leslie
authors.initials: L
authors.lastname: Bernstein
authors.forename: Ivonne E
authors.initials: IE
authors.lastname: Villalobos
authors.forename: Martina
authors.initials: M
authors.lastname: Mirlacher
authors.forename: Jian-Yuan
authors.initials: JY
authors.lastname: Zhou
authors.forename: Rooba
authors.initials: R
authors.lastname: Wardeh
authors.forename: Yong-Tian
authors.initials: YT
authors.lastname: Li
authors.forename: Roberta
authors.initials: R
authors.lastname: Guzman
authors.forename: Yanling
authors.initials: Y
authors.lastname: Ma
authors.forename: Jane
authors.initials: J
authors.lastname: Sullivan-Halley
authors.forename: Angela
authors.initials: A
authors.lastname: Santiago
authors.forename: Jinha M
authors.initials: JM
authors.lastname: Park
authors.forename: Alessandro
authors.initials: A
authors.lastname: Riva
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Slamon
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis / Q000235:genetics; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods / Q000592:standards; D017404:In Situ Hybridization, Fluorescence / Q000379:methods / Q000592:standards; D015337:Multicenter Studies as Topic; D011237:Predictive Value of Tests; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000235:genetics*; D015203:Reproducibility of Results; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; D018719:Erb-b2 Receptor Tyrosine Kinases