title: Goals of screening.
abstract: BACKGROUND
  Colorectal cancer is a major target of inquiry into the effectiveness of screening in the control of the disease by earlier detection and possibly reduced incidence after removal of polyps. Four randomized clinical trials are in process to determine the efficacy of fecal occult blood tests (FOBT) in reducing mortality from colorectal cancer.
  
  
  METHODS
  General issues that affect decisions to initiate screening, benefits and risks, and precision of screening are discussed. Trends in incidence, mortality, stage at detection, and survival are reviewed.
  
  
  RESULTS
  Colorectal cancer retains a relatively high incidence and mortality; improvements are occurring in stage of detection and survival. Definitive results from randomized clinical trials on efficacy of screening with FOBT are not yet available.
  
  
  CONCLUSIONS
  Guidelines for colorectal screening of asymptomatic subjects in the general population have been adopted by the American Cancer Society and the National Cancer Institute. Other organizations have concluded there is insufficient evidence to recommend for or against FOBT.
authors.affiliation: School of Hygiene and Public Health, Johns Hopkins University, Baltimore, Maryland.
authors.forename: S
authors.initials: S
authors.lastname: Shapiro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000401:mortality / Q000517:prevention & control*; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening / Q000379:methods / Q000592:standards*; D008875:Middle Aged; D016032:Randomized Controlled Trials as Topic