title: Serum HER 2 extracellular domain level is correlated with tissue HER 2 status in metastatic gastric or gastro-oesophageal junction adenocarcinoma.
abstract: BACKGROUND
  To explore the association between serum human epidermal growth factor receptor 2 (HER 2) extracellular domain (ECD) levels and tissue HER 2 status in metastatic gastric cancer.
  
  
  METHODS
  HER 2 status was retrospectively analyzed in 219 advanced gastric or gastroesophageal junction (GEJ) patients. Serum HER 2 ECD was measured by chemiluminescent assay and tissue HER 2 was assessed by fluorescent in situ hybridisation (FISH) and immunohistochemistry (IHC) assay.
  
  
  RESULTS
  Significant associations were found between serum HER 2 ECD levels and tissue HER 2 status. Twenty-four patients had HER 2 ECD levels >16.35 ng/mL, which has a sensitivity of 51.4% and a specificity of 97.3% to predict tissue HER 2 status. When the cut-off value was increased to 22 ng/mL, then all 12 patients with serum HER 2 ECD levels>22 ng/mL were tissue HER 2 positive, corresponding to a specificity of 100% and a sensitivity of 32.4%. High serum HER 2 ECD levels were strongly associated with the intestinal histological type (Lauren's classification), liver metastasis, multiple metastasis (>2) and increased LDH levels, but not with overall survival.
  
  
  CONCLUSIONS
  The high specificity of the serum HER 2 ECD assay in predicting tissue HER 2 status suggests its potential as a surrogate marker of the HER 2 status in gastric cancer.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China.
authors.forename: Shu-Qin
authors.initials: SQ
authors.lastname: Dai
authors.forename: Xin
authors.initials: X
authors.lastname: An
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Qiong
authors.initials: Q
authors.lastname: Shao
authors.forename: Yong-Chang
authors.initials: YC
authors.lastname: Chen
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Kong
authors.forename: Cui
authors.initials: C
authors.lastname: Chen
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.forename: Hui-Yan
authors.initials: HY
authors.lastname: Luo
authors.forename: Ying
authors.initials: Y
authors.lastname: Liang
authors.forename: Feng-Hua
authors.initials: FH
authors.lastname: Wang
authors.forename: Rui-Hua
authors.initials: RH
authors.lastname: Xu
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Li
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000473:pathology*; D000328:Adult; D000368:Aged; D004943:Esophagogastric Junction / Q000473:pathology*; D005110:Extracellular Space / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D017434:Protein Structure, Tertiary; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000097:blood* / Q000737:chemistry* / Q000378:metabolism; D013274:Stomach Neoplasms / Q000097:blood / Q000473:pathology*; D016019:Survival Analysis
chemical_list: D018719:Erb-b2 Receptor Tyrosine Kinases; C508053:ERBB2 protein, human