title: Validation of 2-mm tissue microarray technology in gastric cancer. Agreement of 2-mm TMAs and full sections for Glut-1 and Hif-1 alpha.
abstract: OBJECTIVE
  Tissue Microarray (TMA) is a widely used method to perform high-throughput immunohistochemical analyses on different tissues by arraying small sample cores from paraffin-fixed tissues into a single paraffin block. TMA-technology has been validated on numerous cancer tissues and also for gastric cancer studies, although it has not been validated for this tumor tissue so far. The objective of this study was to assess, whether the 2-mm TMA-technology is able to provide representative samples of gastric cancer tissue.
  
  
  METHODS
  TMA paraffin blocks were constructed by means of 220 formalin-fixed and paraffin-embedded gastric cancer samples with a sample diameter of 2 mm. The agreement of immunohistochemical stainings of Glut-1 and Hif-1 alpha in TMA sections and the original full sections was calculated using kappa statistics and direct adjustment.
  
  
  RESULTS
  The congruence was substantial for Glut-1 (kappa 0.64) and Hif-1 alpha (kappa 0.70), but with an agreement of only 71% and 52% within the marker-positive cases of the full-section slides.
  
  
  CONCLUSIONS
  Due to tumor heterogeneity primarily, the TMA technology with a 2-mm sample core shows relevant limitations in gastric cancer tissue. Although being helpful for tissue screening purposes, the 2-mm TMA technology cannot be recommended as a method equal to full-section investigations in gastric cancer.
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany felix.berlth@uk-koeln.de.
authors: Felix
authors: F
authors: Berlth
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany.
authors: Stefan P
authors: SP
authors: Mönig
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany.
authors: Hans A
authors: HA
authors: Schlösser
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany.
authors: Martin
authors: M
authors: Maus
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany.
authors: Christoph T H
authors: CT
authors: Baltin
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany.
authors: Alexander
authors: A
authors: Urbanski
authors: Department of Pathology, University of Cologne, Cologne, Germany.
authors: Uta
authors: U
authors: Drebber
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany.
authors: Elfriede
authors: E
authors: Bollschweiler
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany.
authors: Arnulf H
authors: AH
authors: Hölscher
authors: Department of General, Visceral and Cancer Surgery, University of Cologne, Cologne, Germany Department of Pathology, University of Cologne, Cologne, Germany Division of Genome information Sciences, Department of Pediatrics and Rady Children's Hospital, University of California San Diego, La Jolla, CA, U.S.A.
authors: Hakan
authors: H
authors: Alakus
mesh_terms: D001706:Biopsy; D051272:Glucose Transporter Type 1 / Q000032:analysis*; D057166:High-Throughput Screening Assays; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit / Q000032:analysis*; D007150:Immunohistochemistry; D016612:Paraffin Embedding; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000473:pathology; D046888:Tissue Array Analysis / Q000379:methods / Q000592:standards; D016707:Tissue Fixation
chemical_list: D051272:Glucose Transporter Type 1; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit
keywords: Glut-1; Hif-1 alpha; Tissue microarray; gastric cancer