title: Risk of gastric cancer after Roux-en-Y gastric bypass.
abstract: OBJECTIVE
  To evaluate the risk of gastric cancer after Roux-en-Y gastric bypass (RYGB).
  
  
  METHODS
  Rats randomly underwent 1 of the following: RYGB, duodenojejunal bypass (DJB), or a sham operation. Postoperatively, rats underwent a protocol of cancer induction by means of both continuous (200 ppm in tap water for 16 weeks) and intermittent (50-mg/kg intraesophageal injection, once a week, for 12 weeks) administration of N-methyl-N-nitrosourea.
  
  
  METHODS
  Institut de Recherche Contre les Canceurs de l'Appareil Digestif-European Institute of Telesurgery. STUDY ANIMALS: Fifty-five Fischer 344 rats.
  
  
  METHODS
  Seventeen weeks after the operation, we performed a pathologic examination of the whole stomach in all animals to assess for the presence of cancer and/or premalignant lesions. Bilirubin concentration, gastric bacterial flora, and any other pathologic findings were also recorded.
  
  
  RESULTS
  In rats in the sham and DJB groups, the incidence of gastric cancer was 85% and 75%, respectively (P = .63), whereas only 23% of rats in the RYGB group developed gastric cancer (4-fold reduction; P = .002). The remnant stomach of rats in the RYGB group also showed a lower bilirubin concentration (P < .01) and a lower bacterial count (P < .05) compared with both the DJB and sham groups.
  
  
  CONCLUSIONS
  This study shows that RYGB reduces the risk of gastric cancer in an experimental model of dietary-induced carcinogenesis. Lack of direct contact with carcinogens, lower bile reflux, and a lower bacteria concentration in the gastric content may be responsible for these observations. These data suggest that RYGB may be a safe option for the treatment of morbid obesity even in areas with high gastric cancer incidence.
authors.affiliation: Institut de Recherche Contre les Canceurs de l'Appareil Digestif-European Institute of Telesurgery, 1 Place de l'Hopital, 67091 Strasbourg, France.
authors.forename: Harutaka
authors.initials: H
authors.lastname: Inoue
authors.forename: Francesco
authors.initials: F
authors.lastname: Rubino
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Shimada
authors.forename: Véronique
authors.initials: V
authors.lastname: Lindner
authors.forename: Masako
authors.initials: M
authors.lastname: Inoue
authors.forename: Philippe
authors.initials: P
authors.lastname: Riegel
authors.forename: Jacques
authors.initials: J
authors.lastname: Marescaux
mesh_terms: D000818:Animals; D001663:Bilirubin / Q000378:metabolism; D004195:Disease Models, Animal; D015390:Gastric Bypass; D005750:Gastric Juice / Q000378:metabolism / Q000382:microbiology; D018530:Gastric Stump / Q000473:pathology / Q000503:physiopathology; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344; D018570:Risk Assessment; D013274:Stomach Neoplasms / Q000209:etiology* / Q000378:metabolism / Q000517:prevention & control*
chemical_list: D001663:Bilirubin