title: Impact of screening colonoscopy on outcomes in colon cancer surgery.
abstract: OBJECTIVE
  Screening colonoscopy seemingly decreases colorectal cancer rates in the United States. In addition to removing benign lesions and preventing progression to malignancy, screening colonoscopy theoretically identifies asymptomatic patients with early-stage disease, potentially leading to higher survival rates.
  
  
  OBJECTIVE
  To assess the effect of screening colonoscopy on outcomes of colon cancer surgery by reviewing differences in staging, disease-free interval, risk of recurrence, and survival and to identify whether diagnosis through screening improves long-term outcomes independent of staging.
  
  
  METHODS
  Retrospective review of prospectively maintained, institutional review board-approved database.
  
  
  METHODS
  Tertiary care center with high patient volume.
  
  
  METHODS
  All patients who underwent colon cancer surgery at Massachusetts General Hospital from January 1, 2004, through December 31, 2011.
  
  
  METHODS
  Colon cancer surgery.
  
  
  METHODS
  Postoperative staging, death, and recurrence, measured as incidence and time to event.
  
  
  RESULTS
  A total of 1071 patients were included, with 217 diagnosed through screening. Patients not diagnosed through screening were at risk for a more invasive tumor (≥T3: relative risk [RR] = 1.96; P < .001), nodal disease (RR = 1.92; P < .001), and metastatic disease on presentation (RR = 3.37; P < .001). In follow-up, these patients had higher death rates (RR = 3.02; P < .001) and recurrence rates (RR = 2.19; P = .004) as well as shorter survival (P < .001) and disease-free intervals (P < .001). Cox and logistic regression controlling for staging and baseline characteristics revealed that death rate (P = .02) and survival duration (P = .01) were better stage for stage with diagnosis through screening. Death and metastasis rates also remained significantly lower in tumors without nodal or metastatic spread (all P < .001).
  
  
  CONCLUSIONS
  Patients with colon cancer identified on screening colonoscopy not only have lower-stage disease on presentation but also have better outcomes independent of their staging. Compliance to screening colonoscopy guidelines can play an important role in prolonging longevity, improving quality of life, and reducing health care costs through early detection of colon cancer.
authors.affiliation: Division of General and Gastrointestinal Surgery, Massachusetts General Hospital and Harvard Medical School, Boston.
authors.forename: Ramzi
authors.initials: R
authors.lastname: Amri
authors.forename: Liliana G
authors.initials: LG
authors.lastname: Bordeianou
authors.forename: Patricia
authors.initials: P
authors.lastname: Sylla
authors.forename: David L
authors.initials: DL
authors.lastname: Berger
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000401:mortality* / Q000601:surgery; D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000401:mortality* / Q000601:surgery; D003113:Colonoscopy; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D009367:Neoplasm Staging; D012189:Retrospective Studies; D015996:Survival Rate; D016896:Treatment Outcome