title: Cholelithiasis is a risk factor for colorectal adenoma.
abstract: OBJECTIVE
  Postcholecystectomy patients show moderate risk of colorectal cancer. However, few studies have investigated the relationship between cholelithiasis and colorectal adenoma. We examined this possibility through a combination of colonoscopy and ultrasonography in asymptomatic Japanese.
  
  
  METHODS
  We reviewed a subgroup of subjects drawn from a prospective annual colonoscopy screening survey. Subjects who underwent both ultrasonography and colonoscopy, and completed a questionnaire regarding lifestyle habits were entered. We investigated whether subjects with cholelithiasis or a previous cholecystectomy showed an increased risk of colorectal adenoma, as compared with subjects with normal gallbladders.
  
  
  RESULTS
  Data of 4,458 subjects (men 3,053, women 1,405, mean age +/- SD 46.1 +/- 8.62 yr) were analyzed. Cholelithiasis was detected in 206 subjects, 4,189 subjects had normal gallbladders, and 63 subjects had cholecystectomies. The prevalence of colorectal adenoma was 29.6% (61/206) in subjects with cholelithiasis, which was significantly higher when compared with normal subjects, with a prevalence of 17.7% (741/4,189, P < 0.001). In cholecystectomy patients, only 15.9% (10/63) developed colorectal adenomas, which was not significantly different from the control group. In a multivariate analysis controlling for sex, age, family history of colorectal cancer, alcohol, smoking, and body mass index, cholelithiasis was shown to be an independent risk factor for colorectal adenoma (adjusted OR 1.57, 95% CI 1.14-2.18). Cholelithiasis was strongly associated with multiple (> or = 3 lesions, adjusted OR 2.39, 95% CI 1.21-4.72) and left-sided colorectal adenomas (adjusted OR 1.82, 95% CI 1.28-2.59).
  
  
  CONCLUSIONS
  Cholelithiasis is a risk factor for colorectal adenoma.
authors.affiliation: Department of Gastroenterology, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Jaqan.
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamaji
authors.forename: Makoto
authors.initials: M
authors.lastname: Okamoto
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Yoshida
authors.forename: Takao
authors.initials: T
authors.lastname: Kawabe
authors.forename: Ryoichi
authors.initials: R
authors.lastname: Wada
authors.forename: Toru
authors.initials: T
authors.lastname: Mitsushima
authors.forename: Masao
authors.initials: M
authors.lastname: Omata
mesh_terms: D000236:Adenoma / Q000209:etiology*; D002769:Cholelithiasis / Q000150:complications*; D015179:Colorectal Neoplasms / Q000209:etiology*; D006801:Humans; D012307:Risk Factors