Population-Based Colonoscopy Screening for Colorectal Cancer: A Randomized Clinical Trial.

IMPORTANCE Although some countries have implemented widespread colonoscopy screening, most European countries have not introduced it because of uncertainty regarding participation rates, procedure-related pain and discomfort, endoscopist performance, and effectiveness. To our knowledge, no randomized trials on colonoscopy screening currently exist. OBJECTIVE To investigate participation rate, adenoma yield, performance, and adverse events of population-based colonoscopy screening in several European countries. DESIGN, SETTING, AND POPULATION A population-based randomized clinical trial was conducted among 94 959 men and women aged 55 to 64 years of average risk for colon cancer in Poland, Norway, the Netherlands, and Sweden from June 8, 2009, to June 23, 2014. INTERVENTIONS Colonoscopy screening or no screening. MAIN OUTCOMES AND MEASURES Participation in colonoscopy screening, cancer and adenoma yield, and participant experience. Study outcomes were compared by country and endoscopist. RESULTS Of 31 420 eligible participants randomized to the colonoscopy group, 12 574 (40.0%) underwent screening. Participation rates were 60.7% in Norway (5354 of 8816), 39.8% in Sweden (486 of 1222), 33.0% in Poland (6004 of 18 188), and 22.9% in the Netherlands (730 of 3194) (P < .001). The cecum intubation rate was 97.2% (12 217 of 12 574), with 9726 participants (77.4%) not receiving sedation. Of the 12 574 participants undergoing colonoscopy screening, we observed 1 perforation (0.01%), 2 postpolypectomy serosal burns (0.02%), and 18 cases of bleeding owing to polypectomy (0.14%). Sixty-two individuals (0.5%) were diagnosed with colorectal cancer and 3861 (30.7%) had adenomas, of which 1304 (10.4%) were high-risk adenomas. Detection rates were similar in the proximal and distal colon. Performance differed significantly between endoscopists; recommended benchmarks for cecal intubation (95%) and adenoma detection (25%) were not met by 6 (17.1%) and 10 of 35 endoscopists (28.6%), respectively. Moderate or severe abdominal pain after colonoscopy was reported by 601 of 3611 participants (16.7%) examined with standard air insufflation vs 214 of 5144 participants (4.2%) examined with carbon dioxide (CO2) insufflation (P < .001). CONCLUSIONS AND RELEVANCE Colonoscopy screening entails high detection rates in the proximal and distal colon. Participation rates and endoscopist performance vary significantly. Postprocedure abdominal pain is common with standard air insufflation and can be significantly reduced by using CO2. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00883792.

[1]  E. Kuipers,et al.  Colorectal cancer screening: a global overview of existing programmes , 2015, Gut.

[2]  M. Kaminski,et al.  Effectiveness, training and quality assurance of colonoscopy screening for colorectal cancer , 2015, Gut.

[3]  C. Mathers,et al.  Cancer incidence and mortality worldwide: Sources, methods and major patterns in GLOBOCAN 2012 , 2015, International journal of cancer.

[4]  M. Hernán,et al.  Effect of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: a randomized clinical trial. , 2014, JAMA.

[5]  Atle Fretheim,et al.  Flexible sigmoidoscopy versus faecal occult blood testing for colorectal cancer screening in asymptomatic individuals. , 2013, The Cochrane database of systematic reviews.

[6]  M. Bretthauer,et al.  Risk stratification to predict pain during unsedated colonoscopy: results of a multicenter cohort study , 2013, Endoscopy.

[7]  J. V Schönfeld [Colonoscopy versus fecal immunochemical testing in colorectal cancer screening]. , 2013, Zeitschrift fur Gastroenterologie.

[8]  J Austoker,et al.  European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition – Communication , 2012, Endoscopy.

[9]  M. Hernán,et al.  The NordICC Study: Rationale and design of a randomized trial on colonoscopy screening for colorectal cancer , 2012, Endoscopy.

[10]  Mark P Purdue,et al.  Colorectal-cancer incidence and mortality with screening flexible sigmoidoscopy. , 2012, The New England journal of medicine.

[11]  Á. Lanas,et al.  Colonoscopy versus fecal immunochemical testing in colorectal-cancer screening. , 2012, The New England journal of medicine.

[12]  J. Wu,et al.  The role of carbon dioxide insufflation in colonoscopy: a systematic review and meta-analysis , 2012, Endoscopy.

[13]  Paul Fockens,et al.  Participation and yield of colonoscopy versus non-cathartic CT colonography in population-based screening for colorectal cancer: a randomised controlled trial. , 2012, The Lancet. Oncology.

[14]  L. Bisanti,et al.  Once-only sigmoidoscopy in colorectal cancer screening: follow-up findings of the Italian Randomized Controlled Trial--SCORE. , 2011, Journal of the National Cancer Institute.

[15]  C. Mathers,et al.  Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008 , 2010, International journal of cancer.

[16]  Cancer,et al.  Once-only flexible sigmoidoscopy screening in prevention of colorectal cancer: a multicentre randomised controlled trial , 2010, The Lancet.

[17]  J. Lellouch,et al.  Explanatory and pragmatic attitudes in therapeutical trials. , 1967, Journal of chronic diseases.

[18]  B. Hofstad [Explosion in rectum]. , 2007, Tidsskrift for den Norske laegeforening : tidsskrift for praktisk medicin, ny raekke.

[19]  J. Reguła,et al.  Colonoscopy in colorectal-cancer screening for detection of advanced neoplasia. , 2006, The New England journal of medicine.

[20]  M. Bretthauer,et al.  The Norwegian Gastronet project: Continuous quality improvement of colonoscopy in 14 Norwegian centres , 2006, Scandinavian journal of gastroenterology.

[21]  D. Rex,et al.  Sedation and the technical performance of colonoscopy. , 2005, Gastrointestinal endoscopy clinics of North America.

[22]  A. McMahon Study control, violators, inclusion criteria and defining explanatory and pragmatic trials , 2002, Statistics in medicine.

[23]  J. Wardle,et al.  Single flexible sigmoidoscopy screening to prevent colorectal cancer: baseline findings of a UK multicentre randomised trial , 2002, The Lancet.

[24]  M. Bretthauer,et al.  Endoscopy Continuous Evaluation of Patient Satisfaction in Endoscopy Centres , 2002, Scandinavian journal of gastroenterology.

[25]  L M Schuman,et al.  The effect of fecal occult-blood screening on the incidence of colorectal cancer. , 2000, The New England journal of medicine.