title: Helicobacter pylori infection increases the risk of colorectal adenoma and adenocarcinoma, especially in women.
abstract: BACKGROUND
  Recent reports suggest that Helicobacter pylori infection can potentially increase the risk of colorectal cancer. The purpose of this study was to assess the association between H. pylori infection and the risk of colorectal adenoma and adenocarcinoma, and to evaluate any differences on the basis of sex.
  
  
  METHODS
  The subjects were 669 (40- to 80-year-old) patients who underwent both barium enema examination and total colonoscopy, and who were evaluated for H. pylori infection by (13)C-urea breath test, urease test, or histological diagnosis of biopsied gastric specimens. There were 142 H. pylori-negative and 527-positive patients. The odds ratios (ORs) for H. pylori-positive patients with colorectal adenoma and adenocarcinoma, and for tumor patients with either adenoma or adenocarcinoma were calculated.
  
  
  RESULTS
  Among the H. pylori-negative patients, there were 52 patients without tumor, 63 with adenoma, 27 with adenocarcinoma, and 90 with tumor. Among the H. pylori-positive patients, there were 136, 264, 127, and 391 patients respectively. Pooling all subjects, those infected with H. pylori had a significantly increased OR for adenoma, adenocarcinoma, or tumor, compared to H. pylori-free patients (OR, 1.60, 1.80, and 1.66, respectively). For female H. pylori-positive subjects, the risk of having adenocarcinoma or tumor was significantly higher than that for their H. pylori-free counterparts, while for male H. pylori-positive and -negative subjects, there was no such significant difference.
  
  
  CONCLUSIONS
  The results therefore suggest that, in patients aged 40-80 years, H. pylori infection increased the risk of colorectal adenoma and adenocarcinoma, with significantly higher risks for female patients.
authors.affiliation: Third Department of Internal Medicine, Nippon Medical School, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan.
authors.forename: Shunji
authors.initials: S
authors.lastname: Fujimori
authors.forename: Teruyuki
authors.initials: T
authors.lastname: Kishida
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Yoshihisa
authors.initials: Y
authors.lastname: Sekita
authors.forename: Tsuguhiko
authors.initials: T
authors.lastname: Seo
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nagata
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tatsuguchi
authors.forename: Katya
authors.initials: K
authors.lastname: Gudis
authors.forename: Kimiyoshi
authors.initials: K
authors.lastname: Yokoi
authors.forename: Noritake
authors.initials: N
authors.lastname: Tanaka
authors.forename: Kiyohiko
authors.initials: K
authors.lastname: Yamashita
authors.forename: Takashi
authors.initials: T
authors.lastname: Tajiri
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Ohaki
authors.forename: Choitsu
authors.initials: C
authors.lastname: Sakamoto
mesh_terms: D000230:Adenocarcinoma / Q000209:etiology* / Q000473:pathology; D000236:Adenoma / Q000209:etiology* / Q000473:pathology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000473:pathology; D005260:Female; D016481:Helicobacter Infections / Q000150:complications* / Q000382:microbiology / Q000473:pathology; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors