title: Increased estrogen receptor and epidermal growth factor receptor gene product co-expression in surgically resected gastric adenocarcinomas.
abstract: BACKGROUND
  Evidence exists that estrogens influence the action of epidermal growth factor (EGF) and its receptor (EGF-R) at multiple levels. Estrogen and antiestrogen action on gastric and other gastrointestinal malignancies has been evaluated by several groups with conflicting results, and EGF-R has been implicated in the current growth factor-mediated models for gastric cancer progression.
  
  
  METHODS
  ERs and EGF-Rs were detected immunohistochemically in a total of 53 advanced gastric carcinomas using monoclonal antibodies (mAbs) to human ERs and EGF-Rs.
  
  
  RESULTS
  ERs were expressed in 30 (56%) and EGF-Rs in 20 (38%) of the gastric tumors. ER(+) gastric tumors were closely associated with the intestinal type (P < 0.01), whereas EGF-R(+) tumors were significantly correlated with poor differentiation status and ER(+) expression (P < 0.01). Of EGF-R(+) tumors, 85% were also ER(+). EGF-R and ER co-expression was demonstrated in 17 tumors (32% of the group). These cases were significantly corelated with poor differentiation and large tumor size upon resection (P < 0.05).
  
  
  CONCLUSIONS
  ER and EGF-R co-expression indicates that a functional interaction between estrogens and EGF may exist in gastric cancer and that when such an interaction becomes operative, it may lead to dedifferentiation and increased tumor growth.
authors.affiliation: 1st Department of Propedeutic Surgery, Athens Medical School, Hippocration General Hospital, Greece.
authors.forename: G J
authors.initials: GJ
authors.lastname: Koullias
authors.forename: G P
authors.initials: GP
authors.lastname: Kouraklis
authors.forename: I S
authors.initials: IS
authors.lastname: Raftopoulos
authors.forename: P S
authors.initials: PS
authors.lastname: Davaris
authors.forename: S A
authors.initials: SA
authors.lastname: Papadopoulos
authors.forename: B C
authors.initials: BC
authors.lastname: Golematis
mesh_terms: D000230:Adenocarcinoma / Q000737:chemistry* / Q000601:surgery; D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D066246:ErbB Receptors / Q000032:analysis* / Q000276:immunology; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D011960:Receptors, Estrogen / Q000032:analysis* / Q000276:immunology; D013274:Stomach Neoplasms / Q000737:chemistry* / Q000601:surgery; D015854:Up-Regulation
chemical_list: D000911:Antibodies, Monoclonal; D011960:Receptors, Estrogen; D066246:ErbB Receptors