title: Marked differences in the frequency of microsatellite instability in gastric cancer from different countries.
abstract: OBJECTIVE
  Previous studies have reported variable rates of microsatellite instability (MSI) in gastric cancer. We investigated the frequency of MSI in invasive gastric carcinoma of patients from three geographic regions.
  
  
  METHODS
  Genomic DNA from gastric cancer and nontumor tissue from 22 Korean, 20 Colombian, and 26 U.S. patients was amplified with five microsatellite markers.
  
  
  RESULTS
  MSI was more frequently seen in gastric cancer from Korea, affecting 50% of patients, in contrast with gastric cancers from the U.S. (7%) and Colombia (15%) (p = 0.003 and p = 0.03, respectively). MSI at one locus was significantly more frequent in gastric cancer from individuals >65 yr (p = 0.01). MSI was similarly associated with both diffuse and intestinal types of gastric cancer.
  
  
  CONCLUSIONS
  MSI affects the two major histological types of gastric cancer, and was more frequent in gastric cancer from Korea than in the other countries, suggesting that the relative importance of different pathways of gastric carcinogenesis may vary in diverse regions of the world.
authors.affiliation: Department of Medicine, Veterans Affairs Medical Center and Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Sepulveda
authors.forename: A C
authors.initials: AC
authors.lastname: Santos
authors.forename: Y
authors.initials: Y
authors.lastname: Yamaoka
authors.forename: L
authors.initials: L
authors.lastname: Wu
authors.forename: O
authors.initials: O
authors.lastname: Gutierrez
authors.forename: J G
authors.initials: JG
authors.lastname: Kim
authors.forename: D Y
authors.initials: DY
authors.lastname: Graham
mesh_terms: D000368:Aged; D000483:Alleles; D002277:Carcinoma / Q000235:genetics*; D003105:Colombia; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006801:Humans; D007723:Korea; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D016133:Polymerase Chain Reaction; D013274:Stomach Neoplasms / Q000235:genetics*; D014481:United States