A randomized study on colorectal cancer screening (NORCCAP)

NORCCAP (Norwegian Colorectal Cancer Prevention) is a randomized study on screening for colorectal cancer (CRC) and polyps (potential precursor lesions for colorectal cancer).
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The NORCCAP project is a randomized study on screening for, and prevention of, colorectal cancer (CRC). NORCCAP was also a pilot on a possible national screening program. The project was initiated by the Norwegian Gastrointestinal Cancer Group (NGICG) and the Norwegian Cancer Society with shared funding between the Norwegian Cancer Society and the Ministry of Health and Care Services. The Cancer Registry took over the ownership of NORCCAP in 2002. The study was started and carried out under the leadership of Geir Hoff.

The screening examinations were carried out over the course of three years (1999-2001) in Oslo and Telemark. 21,000 women and men aged 50-64, living in Oslo and Telemark, were randomly drawn from the population registry and offered a screening examination by flexible sigmoidoscopy (flexible endoscope for examination of the distal 50-60 cm of the large intestine). The rest of the population in this age range (n=79,000) constituted the control group. Half of the invitees were asked to deliver a stool sample for supplementary screening for blood in the feces (FOB-testing with an immunochemical test – FlexSure OBT®) and for research purposes to develop new stool-based screening methods. In line with this, blood samples were also taken. Participants have been followed over time.



So far, 66 original articles and 12 Ph.D theses have been published. Much of the research done has been of great value also to routine clinical activity. The quality assurance program in NORCCAP-I has developed further into a separate programme - Gastronet – a network for quality development in gastrointestinal endoscopy in Norway. Gastronet has become one of the national quality assurance programs of the Norwegian Directorate of Health and the official quality assurance platform for the Norwegian Gastroenterology Society.


Bretthauer M, Gondal G, Larsen K, Carlsen E, Eide TJ, Grotmol T, Skovlund E, Tveit KM, Vatn MH, Hoff G. Design, organization and management of a controlled population screening study for detection of colorectal neoplasia: attendance rates in the NORCCAP study (Norwegian Colorectal Cancer Prevention). Scand J Gastroenterol. 2002 May;37(5):568-73. doi: 10.1080/00365520252903125. PMID: 12059059.

Gondal G, Grotmol T, Hofstad B, Bretthauer M, Eide TJ, Hoff G. The Norwegian Colorectal Cancer Prevention (NORCCAP) screening study: baseline findings and implementations for clinical work-up in age groups 50-64 years. Scand J Gastroenterol. 2003 Jun;38(6):635-42. doi: 10.1080/00365520310003002. PMID: 12825872.

Hoff G, Grotmol T, Skovlund E, Bretthauer M; Norwegian Colorectal Cancer Prevention Study Group. Risk of colorectal cancer seven years after flexible sigmoidoscopy screening: randomised controlled trial. BMJ. 2009 May 29;338:b1846. doi: 10.1136/bmj.b1846. PMID: 19483252; PMCID: PMC2688666.

Holme Ø, Løberg M, Kalager M, Bretthauer M, Hernán MA, Aas E, Eide TJ, Skovlund E, Schneede J, Tveit KM, Hoff G. Effect of flexible sigmoidoscopy screening on colorectal cancer incidence and mortality: a randomized clinical trial. JAMA. 2014 Aug 13;312(6):606-15. doi: 10.1001/jama.2014.8266. Erratum in: JAMA. 2014 Sep 3;312(9):964. PMID: 25117129; PMCID: PMC4495882.

Berstad P, Løberg M, Larsen IK, Kalager M, Holme Ø, Botteri E, Bretthauer M, Hoff G. Long-term lifestyle changes after colorectal cancer screening: randomised controlled trial. Gut. 2015 Aug;64(8):1268-76. doi: 10.1136/gutjnl-2014-307376. Epub 2014 Sep 2. PMID: 25183203.

Holme Ø, Bretthauer M, Eide TJ, Løberg EM, Grzyb K, Løberg M, Kalager M, Adami HO, Kjellevold Ø, Hoff G. Long-term risk of colorectal cancer in individuals with serrated polyps. Gut. 2015 Jun;64(6):929-36. doi: 10.1136/gutjnl-2014-307793. Epub 2014 Nov 16. PMID: 25399542.

Holme Ø, Løberg M, Kalager M, Bretthauer M, Hernán MA, Aas E, Eide TJ, Skovlund E, Lekven J, Schneede J, Tveit KM, Vatn M, Ursin G, Hoff G; NORCCAP Study Group†. Long-Term Effectiveness of Sigmoidoscopy Screening on Colorectal Cancer Incidence and Mortality in Women and Men: A Randomized Trial. Ann Intern Med. 2018 Jun 5;168(11):775-782. doi: 10.7326/M17-1441. Epub 2018 Apr 24. PMID: 29710125; PMCID: PMC6853067.


See all NORCCAP publications