title: Gastric mucosa in Mongolian and Japanese patients with gastric cancer and Helicobacter pylori infection.
abstract: OBJECTIVE
  To investigate the characteristics of gastric cancer and gastric mucosa in a Mongolian population by comparison with a Japanese population.
  
  
  METHODS
  A total of 484 Mongolian patients with gastric cancer were enrolled to study gastric cancer characteristics in Mongolians. In addition, a total of 208 Mongolian and 3205 Japanese consecutive outpatients who underwent endoscopy, had abdominal complaints, no history of gastric operation or Helicobacter pylori eradication treatment, and no use of gastric secretion inhibitors such as histamine H2-receptor antagonists or proton pump inhibitors were enrolled. This study was conducted with the approval of the ethics committees of all hospitals. The triple-site biopsy method was used for the histologic diagnosis of gastritis and H. pylori infection in all Mongolian and Japanese cases. The infection rate of H. pylori and the status of gastric mucosa in H. pylori-infected patients were compared between Mongolian and Japanese subjects. Age (± 5 years), sex, and endoscopic diagnosis were matched between the two countries.
  
  
  RESULTS
  Approximately 70% of Mongolian patients with gastric cancer were 50-79 years of age, and approximately half of the cancers were located in the upper part of the stomach. Histologically, 65.7% of early cancers exhibited differentiated adenocarcinoma, whereas 73.9% of advanced cancers displayed undifferentiated adenocarcinoma. The infection rate of H. pylori was higher in Mongolian than Japanese patients (75.9% vs 48.3%, P < 0.0001). When stratified by age, the prevalence was highest among young patients, and tended to decrease in patients aged 50 years or older. The anti-East-Asian CagA-specific antibody was negative in 99.4% of H. pylori-positive Mongolian patients. Chronic inflammation, neutrophil activity, glandular atrophy, and intestinal metaplasia scores were significantly lower in Mongolian compared to Japanese H. pylori-positive patients (P < 0.0001), with the exception of the intestinal metaplasia score of specimen from the greater curvature of the upper body. The type of gastritis changed from antrum-predominant gastritis to corpus-predominant gastritis with age in both populations.
  
  
  CONCLUSIONS
  Gastric cancer was located in the upper part of the stomach in half of the Mongolian patients; Mongolian patients were infected with non-East-Asian-type H. pylori.
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Matsuhisa
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Yamaoka
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Tomohisa
authors.initials: T
authors.lastname: Uchida
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Davaadorj
authors.initials: D
authors.lastname: Duger
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Battulga
authors.initials: B
authors.lastname: Adiyasuren
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Oyuntsetseg
authors.initials: O
authors.lastname: Khasag
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Tserentogtokh
authors.initials: T
authors.lastname: Tegshee
authors.affiliation: Takeshi Matsuhisa, Department of Gastroenterology, Tama-Nagayama University Hospital, Nippon Medical School, Tokyo 206-8512, Japan.
authors.forename: Byambajav
authors.initials: B
authors.lastname: Tsogt-Ochir
mesh_terms: D000230:Adenocarcinoma / Q000208:ethnology* / Q000382:microbiology / Q000473:pathology; D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D044466:Asian People; D001706:Biopsy; D002454:Cell Differentiation; D005260:Female; D005753:Gastric Mucosa / Q000382:microbiology* / Q000473:pathology*; D005756:Gastritis / Q000208:ethnology / Q000382:microbiology / Q000473:pathology; D005773:Gastroscopy; D016481:Helicobacter Infections / Q000175:diagnosis / Q000208:ethnology* / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification*; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008297:Male; D008679:Metaplasia; D008875:Middle Aged; D008986:Mongolia / Q000453:epidemiology; D015995:Prevalence; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000208:ethnology* / Q000382:microbiology / Q000473:pathology
keywords: Chronic inflammation; Gastric cancer; Glandular atrophy; Helicobacter pylori; Intestinal metaplasia; Japanese; Mongolian; Neutrophil activity; Non-East-Asian-type strain