title: MET amplification is not rare and predicts unfavorable clinical outcomes in patients with recurrent/metastatic gastric cancer after chemotherapy.
abstract: BACKGROUND
  Several large studies have reported an extremely low incidence of MET gene amplification (GA) in patients with radically resected gastric cancer. This study was conducted to evaluate the prevalence and prognostic role of MET in patients with recurrent=metastatic gastric cancer who received chemotherapy.
  
  
  METHODS
  MET GA and protein expression of recurrent=metastatic gastric cancer samples were evaluated by fluorescence in situ hybridization and immunohistochemistry (IHC), respectively.
  
  
  RESULTS
  This retrospective study included 232 patients with recurrent=metastatic gastric cancer. MET GA and strong protein expression(IHC31) were observed in 8.3% (19 of 230 samples) and 9.6% (22 of 229 samples) of samples, respectively. A significant correlation was observed between MET GA and protein expression (r = 0.378; P<.001). MET GA was correlated with poor performance status(P<.001) and poorly differentiated tumors (P=.0015). Both MET GA and IHC 31 expression were associated with a substantially shorter median overall survival (OS) and progression-free survival (PFS). The median OS and PFS for patients with MET GA versus those without MET GA were 5.7 months versus 15.5 months (P<.001) and 3.6 months versus 6.9 months (P<.001), respectively. The median OS and PFS for patients with MET IHC 31 expression versus IHC 0 to 21 expression were 6.3 months versus 15.1 months(P<.001) and 3.6 months versus 7.0 months (P<.001), respectively.
  
  
  CONCLUSIONS
  In patients with recurrent=metastatic gastric cancer,MET amplification and strong protein expression are not rare and appear to be significantly associated with unfavorable clinical outcomes.
authors.affiliation: State Key Laboratory of Oncology in South China, Guangzhou, China; Department of Medical Oncology, Sun Yat-sen University Cancer Center, Guangzhou.
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: Feng-Hua
authors.initials: FH
authors.lastname: Wang
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Wang
authors.forename: Zhi-Qiang
authors.initials: ZQ
authors.lastname: Wang
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: Dong-Sheng
authors.initials: DS
authors.lastname: Zhang
authors.forename: Rui-Hua
authors.initials: RH
authors.lastname: Xu
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Li
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D005260:Female; D005784:Gene Amplification; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis / Q000235:genetics* / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics*; D012189:Retrospective Studies; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics* / Q000473:pathology*; D016896:Treatment Outcome
chemical_list: C491743:MET protein, human; D019859:Proto-Oncogene Proteins c-met