title: FGFR2 Assessment in Gastric Cancer Using Quantitative Real-Time Polymerase Chain Reaction, Fluorescent In Situ Hybridization, and Immunohistochemistry.
abstract: OBJECTIVE
  Fibroblast growth factor receptor 2 (FGFR2) amplification has been reported to be a target for treatment in gastric cancer. However, an optimal tissue source and method for evaluating FGFR2 have yet to be established.
  
  
  METHODS
  Copy numbers were compared by quantitative polymerase chain reaction (qPCR) using frozen vs formalin-fixed, paraffin-embedded (FFPE) tissue and biopsy vs surgical specimens. We correlated the results of qPCR and immunohistochemistry (IHC) with fluorescence in situ hybridization (FISH) using stage IV gastric cancer biopsy specimens and validated the results in surgical specimens.
  
  
  RESULTS
  FFPE tissues were suitable for qPCR, and biopsy specimens were equivalent to or better than surgical specimens. qPCR and IHC results exhibited an excellent correlation with FISH at eight or more copies by qPCR in any kind of tissue, 5% or more by IHC in biopsy specimens, and 10% or more by IHC in surgical specimens. FGFR2 amplification was 6.6% in stage IV gastric cancers, and 42% of these showed heterogeneous amplification and overexpression. IHC indicated a good correlation with FISH even in the heterogeneous cases.
  
  
  CONCLUSIONS
  FFPE biopsy tissues are an adequate source for FGFR2 evaluation in gastric carcinomas, and a qPCR-based copy number assay can be used for screening. IHC is also a valid and practical method for evaluating FGFR2, considering frequent heterogeneity.
authors.affiliation: From the Department of Pathology.
authors.forename: Young Soo
authors.initials: YS
authors.lastname: Park
authors.affiliation: Asan Institute for Life Science, and.
authors.forename: Young-Soon
authors.initials: YS
authors.lastname: Na
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Republic of Korea.
authors.forename: Min-Hee
authors.initials: MH
authors.lastname: Ryu
authors.affiliation: Asan Institute for Life Science, and.
authors.forename: Chae-Won
authors.initials: CW
authors.lastname: Lee
authors.affiliation: From the Department of Pathology.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Park
authors.affiliation: Asan Institute for Life Science, and.
authors.forename: Ju-Kyung
authors.initials: JK
authors.lastname: Lee
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Republic of Korea.
authors.forename: Sook Ryun
authors.initials: SR
authors.lastname: Park
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Republic of Korea.
authors.forename: Baek-Yeol
authors.initials: BY
authors.lastname: Ryoo
authors.affiliation: Department of Oncology, Asan Medical Center, University of Ulsan College of Medicine, Republic of Korea. ykkang@amc.seoul.kr.
authors.forename: Yoon-Koo
authors.initials: YK
authors.lastname: Kang
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics*; D000368:Aged; D005260:Female; D018628:Gene Dosage; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D060888:Real-Time Polymerase Chain Reaction; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000032:analysis* / Q000235:genetics*; D013274:Stomach Neoplasms / Q000235:genetics*
chemical_list: C496353:FGFR2 protein, human; D051497:Receptor, Fibroblast Growth Factor, Type 2
keywords: FGFR2; Fluorescence in situ hybridization; Gastric carcinoma; Immunohistochemistry; Quantitative real-time polymerase chain reaction