title: Intraoperative diagnosis of lymph node metastasis by transcription-reverse transcription concerted reaction assay in gastric cancer.
abstract: BACKGROUND
  Increasing evidence has been accumulated to substantiate the clinical usefulness of quantitative evaluation of gene expression. This study was undertaken to assess diagnosis of metastasis in dissected lymph nodes through quantitative evaluation of the expression of carcinoembryonic antigen mRNA (CEA mRNA) by a rapid, simple transcription-reverse transcription concerted reaction (TRC) assay using dissected lymph node washings.
  
  
  METHODS
  A total of 110 dissected lymph nodes from 40 patients undergoing surgery for gastric cancer were studied. Each dissected lymph node was cut crosswise and washed with physiological saline. The washings were assayed for CEA mRNA and the assay results were assessed in comparison with the pathological diagnosis [hematoxylin and eosin (H&E) staining]. All lymph nodes were also subjected to immunostaining for cytokeratin (CK staining) and assessed comparatively.
  
  
  RESULTS
  By H&E staining, 29 lymph nodes were found to be positive and 81 to be negative for metastasis. By TRC assay, 38 lymph nodes were found to be positive and 72 to be negative. According to the results of CK staining, there were 37 metastasis-positive lymph nodes and 73 negative nodes. The sensitivity and specificity of H&E staining relative to those of CK staining were 78.4 and 100 %, respectively, while the sensitivity and specificity of TRC assay relative to those of CK staining were 91.9 and 94.5 %, respectively.
  
  
  CONCLUSIONS
  The TRC assay method using lymph node washings is a rapid, simple genetic diagnosis with greater sensitivity than conventional diagnosis by H&E staining of permanent specimens, and enables conservation of lymph nodes in toto as permanent specimens. This TRC method would enable rapid diagnosis even in town hospitals where no pathologist is ordinarily stationed, and is considered to contribute to the clinical application of the sentinel node theory of gastric cancer treatment.
authors.affiliation: Department of Surgery II, Tokyo Women's Medical University, 8-1 Kawadacho, Shinjyuku-ku, Tokyo, 162-8666, Japan.
authors.forename: Ryouichi
authors.initials: R
authors.lastname: Hirayama
authors.forename: Akiyoshi
authors.initials: A
authors.lastname: Seshimo
authors.forename: Kunitomo
authors.initials: K
authors.lastname: Miyake
authors.forename: Masako
authors.initials: M
authors.lastname: Nishizawa
authors.forename: Shingo
authors.initials: S
authors.lastname: Kameoka
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002272:Carcinoembryonic Antigen / Q000235:genetics*; D005260:Female; D006801:Humans; D007432:Intraoperative Period; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D012680:Sensitivity and Specificity; D013274:Stomach Neoplasms / Q000473:pathology* / Q000601:surgery*
chemical_list: D002272:Carcinoembryonic Antigen