title: Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths.
abstract: BACKGROUND
  In the National Polyp Study (NPS), colorectal cancer was prevented by colonoscopic removal of adenomatous polyps. We evaluated the long-term effect of colonoscopic polypectomy in a study on mortality from colorectal cancer.
  
  
  METHODS
  We included in this analysis all patients prospectively referred for initial colonoscopy (between 1980 and 1990) at NPS clinical centers who had polyps (adenomas and nonadenomas). The National Death Index was used to identify deaths and to determine the cause of death; follow-up time was as long as 23 years. Mortality from colorectal cancer among patients with adenomas removed was compared with the expected incidence-based mortality from colorectal cancer in the general population, as estimated from the Surveillance Epidemiology and End Results (SEER) Program, and with the observed mortality from colorectal cancer among patients with nonadenomatous polyps (internal control group).
  
  
  RESULTS
  Among 2602 patients who had adenomas removed during participation in the study, after a median of 15.8 years, 1246 patients had died from any cause and 12 had died from colorectal cancer. Given an estimated 25.4 expected deaths from colorectal cancer in the general population, the standardized incidence-based mortality ratio was 0.47 (95% confidence interval [CI], 0.26 to 0.80) with colonoscopic polypectomy, suggesting a 53% reduction in mortality. Mortality from colorectal cancer was similar among patients with adenomas and those with nonadenomatous polyps during the first 10 years after polypectomy (relative risk, 1.2; 95% CI, 0.1 to 10.6).
  
  
  CONCLUSIONS
  These findings support the hypothesis that colonoscopic removal of adenomatous polyps prevents death from colorectal cancer. (Funded by the National Cancer Institute and others.).
authors.affiliation: Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA. zaubera@mskcc.org
authors.forename: Ann G
authors.initials: AG
authors.lastname: Zauber
authors.forename: Sidney J
authors.initials: SJ
authors.lastname: Winawer
authors.forename: Michael J
authors.initials: MJ
authors.lastname: O'Brien
authors.forename: Iris
authors.initials: I
authors.lastname: Lansdorp-Vogelaar
authors.forename: Marjolein
authors.initials: M
authors.lastname: van Ballegooijen
authors.forename: Benjamin F
authors.initials: BF
authors.lastname: Hankey
authors.forename: Weiji
authors.initials: W
authors.lastname: Shi
authors.forename: John H
authors.initials: JH
authors.lastname: Bond
authors.forename: Melvin
authors.initials: M
authors.lastname: Schapiro
authors.forename: Joel F
authors.initials: JF
authors.lastname: Panish
authors.forename: Edward T
authors.initials: ET
authors.lastname: Stewart
authors.forename: Jerome D
authors.initials: JD
authors.lastname: Waye
mesh_terms: D000236:Adenoma / Q000401:mortality / Q000517:prevention & control*; D018256:Adenomatous Polyps / Q000601:surgery*; D000368:Aged; D003111:Colonic Polyps / Q000601:surgery*; D003113:Colonoscopy; D015179:Colorectal Neoplasms / Q000401:mortality / Q000517:prevention & control* / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged