gms | German Medical Science

27th German Cancer Congress Berlin 2006

German Cancer Society (Frankfurt/M.)

22. - 26.03.2006, Berlin

Does a negative screening colonoscopy ever need to be repeated?

Meeting Abstract

  • corresponding author presenting/speaker Hermann Brenner - Deutsches Zentrum für Alternsforschung, Heidelberg
  • Jenny Chang-Claude - Deutsches Krebsforschungszentrum, Heidelberg
  • Christoph M. Seiler - Universitätsklinikum, Heidelberg
  • Til Stürmer - Harvard Medical School, Boston, USA
  • Michael Hoffmeister - Deutsches Zentrum für Alternsforschung, Heidelberg

27. Deutscher Krebskongress. Berlin, 22.-26.03.2006. Düsseldorf, Köln: German Medical Science; 2006. DocPO183

The electronic version of this article is the complete one and can be found online at:

Published: March 20, 2006

© 2006 Brenner et al.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( You are free: to Share – to copy, distribute and transmit the work, provided the original author and source are credited.



Background: In October 2002, screening colonoscopy has been introduced in the German early cancer detection program. In accordance with recommendations from national and international expert panels, people with no findings of polyps are offered repeat colonoscopy after 10 years. There is though very limited empirical evidence regarding the time interval after which colonoscopy with negative findings should be repeated. We aimed to assess the long-term risk of clinically manifest CRC among subjects with negative findings at colonoscopy in a large case-control study.

Methods: Detailed history and results of previous colonoscopies were obtained from 540 cases and 614 controls by personal interviews and validated through medical records in a population-based case-control study conducted in the Rhine-Neckar-Odenwald region since 2003. The relative risk of CRC among subjects with a history of negative colonoscopy compared to subjects w ithout previous colonoscopy was assessed according to time since colonoscopy after control for potential confounding factors.

Results: Subjects with previous negative colonoscopy had a 74% lower risk of CRC than subjects without previous colonoscopy (adjusted odds ratio, aOR, 0.26, 95% confidence interval, CI, 0.16-0.40). This low risk was seen even if the colonoscopy had been performed up to 20 or more years ago. Particularly low risks were seen for sigma cancer (aOR 0.13, 95% CI 0.04-0.43) and for rectum cancer (aOR 0.19, 95% CI 0.09-0.39), and after a negative screening colonoscopy at ages 55-64 (aOR 0.17, 95% CI 0.08-0.39) and older (aOR 0.21, 95% CI 0.10-0.41).

Conclusions: People with negative findings at colonoscopy are at very low risk of CRC and might not need to undergo repeat colonoscopy for 20 years or more, if at all. The possibility to extend screening intervals beyond 10 years might reduce complications, increase feasibility and cost-effectiveness of colonoscopy based screening for colorectal cancer.