title: Colorectal cancer screening: Systematic review of screen-related morbidity and mortality.
abstract: BACKGROUND
  Implementation of mass colorectal cancer screening, using faecal occult blood test or colonoscopy, is recommended by the European Union in order to increase cancer-specific survival by diagnosing disease in an earlier stage. Post-colonoscopy complications have been addressed by previous systematic reviews, but morbidity of colorectal cancer screening on multiple levels has never been evaluated before.
  
  
  OBJECTIVE
  To evaluate potential harm as a result of mass colorectal cancer screening in terms of complications after colonoscopy, morbidity and mortality following surgery, psychological distress and inappropriate use of the screening test.
  
  
  METHODS
  A systematic review of all literature on morbidity and mortality attributed to colorectal cancer screening, using faecal occult blood test or colonoscopy, from each databases' inception to August 2016 was performed. A meta-analysis was conducted to examine the pooled incidence of major complications of colonoscopy (major bleedings and perforations).
  
  
  RESULTS
  Sixty studies were included. Five out of seven included prospective studies on psychological morbidity reported an association between participation in a colorectal screening program and psychological distress. Serious morbidity from colonoscopy in asymptomatic patients included major bleedings (0.8/1000 procedures, 95% CI 0.18-1.63) and perforations (0.07/1000 procedures, 95% CI 0.006-0.17).
  
  
  CONCLUSIONS
  Participation in a colorectal cancer screening program is associated with psychological distress and can cause serious adverse events. Nevertheless, the short duration of psychological impact as well as the low colonoscopy complication rate seems reassuring. Because of limited literature on harms other than perforation and bleeding, future research on this topic is greatly needed to contribute to future screening recommendations.
authors.affiliation: Department of Surgery, Leiden University Medical Center, The Netherlands. Electronic address: N.C.A.Vermeer@lumc.nl.
authors.forename: N C A
authors.initials: NC
authors.lastname: Vermeer
authors.affiliation: Department of Surgery, Leiden University Medical Center, The Netherlands. Electronic address: H.S.Snijders@lumc.nl.
authors.forename: H S
authors.initials: HS
authors.lastname: Snijders
authors.affiliation: Department of Surgery, Leiden University Medical Center, The Netherlands. Electronic address: F.A.Holman@lumc.nl.
authors.forename: F A
authors.initials: FA
authors.lastname: Holman
authors.affiliation: Department of Surgery, Leiden University Medical Center, The Netherlands. Electronic address: G.J.Liefers@lumc.nl.
authors.forename: G J
authors.initials: GJ
authors.lastname: Liefers
authors.affiliation: Department of Surgery, Leiden University Medical Center, The Netherlands. Electronic address: E.Bastiaannet@lumc.nl.
authors.forename: E
authors.initials: E
authors.lastname: Bastiaannet
authors.affiliation: Department of Surgery, Leiden University Medical Center, The Netherlands. Electronic address: C.J.H.van_de_Velde@lumc.nl.
authors.forename: C J H
authors.initials: CJ
authors.lastname: van de Velde
authors.affiliation: Department of Surgery, Leiden University Medical Center, The Netherlands. Electronic address: K.C.M.J.Peeters@lumc.nl.
authors.forename: K C M J
authors.initials: KC
authors.lastname: Peeters
mesh_terms: D003113:Colonoscopy / Q000009:adverse effects / Q000523:psychology / Q000706:statistics & numerical data*; D015179:Colorectal Neoplasms / Q000453:epidemiology* / Q000401:mortality / Q000601:surgery; D006801:Humans; D008403:Mass Screening / Q000523:psychology / Q000706:statistics & numerical data; D009017:Morbidity; D013315:Stress, Psychological
keywords: Colorectal cancer; Morbidity; Review; Screening