title: Colon cancer screening and surveillance controversies.
abstract: OBJECTIVE
  To discuss new colorectal cancer screening tests and highlight controversies regarding colon screening and surveillance.
  
  
  RESULTS
  New screening guidelines were published in 2008. Tests that primarily detect early cancer include sensitive guaiac fecal occult blood test or fecal immunochemical test. Tests that can detect both early cancer and cancer precursor lesions include sigmoidoscopy and colonoscopy. One guideline endorses the use of computed tomographic colonography. Limitations of each test are highlighted in the new guidelines. Controversies include age to start screening, age to stop screening, and appropriate interval after a negative screening colonoscopy. New work has raised some doubt about the protective effect of colonoscopy in the proximal colon. Finally, there is new emphasis on the quality of screening programs.
  
  
  CONCLUSIONS
  Colorectal cancer screening can reduce both incidence and mortality of colorectal cancer if performed with high quality. New work should focus on improving the quality of all screening programs.
authors.affiliation: Division of Gastroenterology and Hepatology, Oregon Health and Science University, Portland, Oregon 97239, USA. lieberma@ohsu.edu
authors.forename: David
authors.initials: D
authors.lastname: Lieberman
mesh_terms: D000367:Age Factors; D023881:Colonography, Computed Tomographic; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000175:diagnosis*; D004273:DNA, Neoplasm / Q000032:analysis; D055088:Early Detection of Cancer; D006138:Guaiac; D006801:Humans; D008403:Mass Screening / Q000379:methods*; D009780:Occult Blood; D017410:Practice Guidelines as Topic; D012812:Sigmoidoscopy
chemical_list: D004273:DNA, Neoplasm; D006138:Guaiac