title: Heterogeneous target protein expression in synchronous multiple gastric carcinomas.
abstract: OBJECTIVE
  To explore the target protein expression in separate tumors in a patient with synchronous multiple gastric carcinomas (SMGCs).
  
  
  METHODS
  Immunohistochemistry for HER2, EGFR, and MET were performed in 282 carcinomas from 141 patients.
  
  
  RESULTS
  Of 141 patients with SMGCs, 11.3%, 23.4%, and 14.9% of cases showed HER2, EGFR, and MET protein overexpression, respectively. In SMGC cases with overexpression of target proteins in > 1 tumor, intertumoral heterogeneity was 81.3% (13/16) for HER2, 78.8% (26/33) for EGFR, and 90.5% (19/21) for MET protein. The concordance rate of HER2, EGFR, and MET expression between 2 carcinomas from the same patient was 90.8%, 81.6%, and 86.5%, respectively, with a kappa value below 0.3, indicating slight to fair agreement.
  
  
  CONCLUSIONS
  We found a considerable intertumoral heterogeneity of target protein overexpression in SMGCs. Our findings support a multicentric origin for SMGC and emphasize the need to perform immunohistochemistry for all synchronous lesions.
authors.affiliation: Department of Pathology, Samsung Medical Center, Sungkyunkwan University School of Medicine, #50, Ilwon-dong, Gangnam-Gu, Seoul 135-710, Korea.
authors.forename: Gyhyun
authors.initials: G
authors.lastname: Kang
authors.forename: Ha Young
authors.initials: HY
authors.lastname: Park
authors.forename: Sumin
authors.initials: S
authors.lastname: Ahn
authors.forename: Kyoung-Mee
authors.initials: KM
authors.lastname: Kim
authors.forename: Cheol Keun
authors.initials: CK
authors.lastname: Park
authors.forename: Min Gew
authors.initials: MG
authors.lastname: Choi
authors.forename: Tae Sung
authors.initials: TS
authors.lastname: Sohn
authors.forename: Jae Moon
authors.initials: JM
authors.lastname: Bae
authors.forename: Sung
authors.initials: S
authors.lastname: Kim
mesh_terms: D000368:Aged; D014408:Biomarkers, Tumor / Q000032:analysis*; D002277:Carcinoma / Q000378:metabolism* / Q000473:pathology*; D066246:ErbB Receptors / Q000032:analysis / Q000096:biosynthesis; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D009378:Neoplasms, Multiple Primary / Q000378:metabolism* / Q000473:pathology; D019859:Proto-Oncogene Proteins c-met / Q000032:analysis / Q000096:biosynthesis; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000032:analysis / Q000096:biosynthesis; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology
chemical_list: D014408:Biomarkers, Tumor; D066246:ErbB Receptors; D019859:Proto-Oncogene Proteins c-met; D018719:Erb-b2 Receptor Tyrosine Kinases; C512478:EGFR protein, human; C508053:ERBB2 protein, human; C491743:MET protein, human