title: Colonoscopic screening of first-degree relatives of patients with large adenomas: increased risk of colorectal tumors.
abstract: OBJECTIVE
  The risk of developing colorectal neoplasia is not well established among family members of individuals with large adenomas, and screening strategies remain under debate in this population. This study aimed at quantifying the risk of colorectal adenomas and cancers using colonoscopic screening in first-degree relatives of patients with large adenomas.
  
  
  METHODS
  This case-control study was performed in 18 endoscopic units of French nonuniversity hospitals. A colonoscopy was offered to first-degree relatives of 306 index cases with adenomas > or =10 mm if they were alive, aged 40-75 years, and could be contacted by the index case. Among them, 168 were examined and matched for age, sex, and geographical area with 2 controls (n = 307). Controls were randomly selected from 1362 consecutive patients aged 40-75 years having undergone a colonoscopy for minor symptoms.
  
  
  RESULTS
  The prevalence of large adenomas and cancers was 8.4% and 4.2%, in relatives and controls, respectively. Odds ratios (ORs) associated with a history of large adenomas in relatives were 2.27 (95% confidence interval [CI], 1.01-5.09) for cancers or large adenomas, 1.21 (95% CI, 0.68-2.15) for small adenomas, and 1.56 (95% CI, 0.96-2.53) for all colorectal neoplasia. The risk of large adenomas and cancers was higher in relatives of index cases younger than 60 years (OR, 3.82; 95% CI, 0.92-15.87) and when the index case had large distal adenomas (OR, 3.14; 95% CI, 1.27-7.73).
  
  
  CONCLUSIONS
  First-degree relatives of patients with large adenomas are at increased risk of developing colorectal cancers or large adenomas. This result has implications for screening in this high-risk population.
authors.affiliation: INSERM Unité 866, Dijon, France.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Cottet
authors.forename: Alexandre
authors.initials: A
authors.lastname: Pariente
authors.forename: Bernard
authors.initials: B
authors.lastname: Nalet
authors.forename: Jacques
authors.initials: J
authors.lastname: Lafon
authors.forename: Chantal
authors.initials: C
authors.lastname: Milan
authors.forename: Sylviane
authors.initials: S
authors.lastname: Olschwang
authors.forename: Catherine
authors.initials: C
authors.lastname: Bonaiti-Pellié
authors.forename: Jean
authors.initials: J
authors.lastname: Faivre
authors.forename: Claire
authors.initials: C
authors.lastname: Bonithon-Kopp
mesh_terms: D000236:Adenoma / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D000328:Adult; D000367:Age Factors; D000368:Aged; D016022:Case-Control Studies; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology; D005190:Family; D005260:Female; D005602:France / Q000453:epidemiology; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods*; D008875:Middle Aged; D009367:Neoplasm Staging; D016017:Odds Ratio; D011237:Predictive Value of Tests; D015995:Prevalence; D018570:Risk Assessment; D012307:Risk Factors