title: Advanced proximal neoplasia of the colon in average-risk adults.
abstract: BACKGROUND
  Estimating risk for advanced proximal neoplasia (APN) based on distal colon findings can help identify asymptomatic persons who should undergo examination of the proximal colon after flexible sigmoidoscopy (FS) screening.
  
  
  OBJECTIVE
  We aimed to determine the risk of APN by most advanced distal finding among an average-risk screening population.
  
  
  METHODS
  Prospective, cross-sectional study.
  
  
  METHODS
  Teaching hospital and colorectal cancer screening center.
  
  
  METHODS
  A total of 4651 asymptomatic persons at average risk for colorectal cancer aged 50 to 74 years (54.4% women [n = 2529] with a mean [± standard deviation] age of 58.4 ± 6.2 years).
  
  
  METHODS
  All participants underwent a complete colonoscopy, including endoscopic removal of all polyps.
  
  
  METHODS
  We explored associations between several risk factors and APN. Logistic regression was used to identify independent predictors of APN.
  
  
  RESULTS
  A total of 142 persons (3.1%) had APN, of whom 85 (1.8%) had isolated APN (with no distal findings). APN was associated with older age, a BMI >27 kg/m(2), smoking, distal advanced adenoma and/or cancer, and distal non-advanced tubular adenoma. Those with a distal advanced neoplasm were more than twice as likely to have APN compared with those without distal lesions.
  
  
  CONCLUSIONS
  Distal findings used to estimate risk of APN were derived from colonoscopy rather than FS itself.
  
  
  CONCLUSIONS
  In persons at average risk for colorectal cancer, the prevalence of isolated APN was low (1.8%). Use of distal findings to predict APN may not be the most effective strategy. However, incorporating factors such as age (>65 years), sex, BMI (>27 kg/m(2)), and smoking status, in addition to distal findings, should be considered for tailoring colonoscopy recommendations. Further evaluation of risk stratification approaches in other asymptomatic screening populations is warranted.
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Prevention and Cancer Control, Cancer Care Ontario, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Linda
authors.initials: L
authors.lastname: Rabeneck
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Lawrence F
authors.initials: LF
authors.lastname: Paszat
authors.affiliation: Department of Medicine, University of Calgary, Calgary, Alberta, Canada.
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Hilsden
authors.affiliation: Alberta Health Services-Cancer Care, Calgary, Alberta, Canada.
authors.forename: S Elizabeth
authors.initials: SE
authors.lastname: McGregor
authors.affiliation: Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario, Canada.
authors.forename: Eugene
authors.initials: E
authors.lastname: Hsieh
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Department of Medicine, University of Toronto, Toronto, Ontario, Canada; Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Jill
authors.initials: J
authors.lastname: M Tinmouth
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada; Institute of Health Policy, Management and Evaluation, University of Toronto, Toronto, Ontario, Canada; Department of Surgery, University of Toronto, Toronto, Ontario, Canada; Department of Surgery and Li Ka Shing Research Institute, St. Michael's Hospital, Toronto, Ontario, Canada.
authors.forename: Nancy N
authors.initials: NN
authors.lastname: Baxter
authors.affiliation: Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada.
authors.forename: Refik
authors.initials: R
authors.lastname: Saskin
authors.affiliation: Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: Arlinda
authors.initials: A
authors.lastname: Ruco
authors.affiliation: Sunnybrook Health Sciences Centre, Toronto, Ontario, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Stock
mesh_terms: D017677:Age Distribution; D000368:Aged; D000553:Ambulatory Care; D002170:Canada / Q000453:epidemiology; D015331:Cohort Studies; D044682:Colon, Ascending / Q000473:pathology*; D003110:Colonic Neoplasms / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology*; D003113:Colonoscopy / Q000379:methods*; D016001:Confidence Intervals; D003430:Cross-Sectional Studies; D018450:Disease Progression; D055088:Early Detection of Cancer / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness / Q000473:pathology; D009367:Neoplasm Staging; D016017:Odds Ratio; D015995:Prevalence; D011446:Prospective Studies; D018570:Risk Assessment; D017678:Sex Distribution; D012812:Sigmoidoscopy / Q000379:methods