Eight Years of Colonoscopic Bowel Cancer Screening in Germany Initial Findings and Projections

Background: Screening colonoscopy has been offered in Germany since the end of 2002. Our aim was to estimate numbers of colorectal cancers prevented or detected early by screening colonoscopy in 2003-2010. Methods: Participation rates and prevalences of advanced adenomas and colorectal cancers at screening colonoscopy in 2003-2008 were obtained from the national screening colonoscopy database by age, sex and calendar year. For 2009 and 2010, levels were assumed to remain at those observed in 2008. These data were combined in Markov models with population figures and estimates of transition rates from advanced adenomas to preclinical colorectal cancer and from preclinical cancer to clinically manifest cancer, accounting for total mortality. Results: An estimated total number of 98 734 cases of colorectal cancer at ages 55-84 years are expected to have been prevented in Germany by removal of advanced adenomas by the end of 2010. These cancers might have become clinically manifest a median time period of 10 years after screening colonoscopy. Another 47 168 cases are expected to have been detected early at screening colonoscopy, often in a curable stage. Conclusion: Despite limited participation, the German screening colonoscopy program makes a major contribution to prevention and early detection of colorectal cancer.