title: Expression profiles of HER2, EGFR, MET and FGFR2 in a large cohort of patients with gastric adenocarcinoma.
abstract: BACKGROUND
  Some tyrosine kinase receptors (RTKs) play critical roles in gastric cancer progression. Not only trastuzumab, but also several other agents targeting RTKs are being investigated for gastric cancer therapy. However, the simultaneous expression of multiple RTKs, which may interfere with the effectiveness of therapeutic agents, has not been evaluated in a large cohort with gastric adenocarcinoma (GAC).
  
  
  METHODS
  We performed a tissue microarray analysis in 950 patients with GAC who underwent a gastrectomy without preoperative chemotherapy. The protein expressions of HER2, EGFR, MET and FGFR2 were evaluated using immunohistochemistry, and the gene amplifications of HER2, EGFR and MET were examined using dual-color in situ hybridization.
  
  
  RESULTS
  The frequency of overexpression was 11.8% for HER2, 23.5% for EGFR, 24.9 % for MET and 31.1% for FGFR2. Whereas strong staining for each of the RTKs was heterogeneous, tumors with homogeneously strong staining areas often exhibited gene amplification. Strong EGFR expression was significantly associated with a poor outcome, but no prognostic correlations were observed in other RTKs. The overexpression of single and multiple RTKs was observed in 40.4 and 22.7% of the cases, respectively. HER2, EGFR, MET and FGFR2 predominance was observed in 10.1, 13.9, 16.1 and 22.9% of the GACs, respectively.
  
  
  CONCLUSIONS
  Approximately two-thirds of patients with GAC exhibited the expression of at least one RTK and would be candidates for targeted therapies. Moreover, one-third of at least one RTK overexspressing cases showed multiple RTKs expression. Our results may be useful for selecting the most suitable patients for each targeted therapy.
authors.affiliation: Division of Pathology, Research Center for Innovative Oncology, National Cancer Center Hospital East, 6-5-1 Kashiwanoha, Kashiwa-city, Chiba, 277-8577, Japan.
authors.forename: Akiko Kawano
authors.initials: AK
authors.lastname: Nagatsuma
authors.forename: Masaki
authors.initials: M
authors.lastname: Aizawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kuwata
authors.forename: Toshihiko
authors.initials: T
authors.lastname: Doi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ohtsu
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Fujii
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ochiai
mesh_terms: D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000401:mortality / Q000556:secondary; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D014408:Biomarkers, Tumor / Q000235:genetics / Q000378:metabolism*; D002291:Carcinoma, Papillary / Q000235:genetics / Q000378:metabolism / Q000401:mortality / Q000556:secondary; D015331:Cohort Studies; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007124:Immunoenzyme Techniques; D017404:In Situ Hybridization, Fluorescence; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D009367:Neoplasm Staging; D011379:Prognosis; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000401:mortality / Q000473:pathology; D015996:Survival Rate; D046888:Tissue Array Analysis
chemical_list: D014408:Biomarkers, Tumor; D066246:ErbB Receptors; D019859:Proto-Oncogene Proteins c-met; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; D051497:Receptor, Fibroblast Growth Factor, Type 2; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C496353:FGFR2 protein, human; C491743:MET protein, human