Colorectal cancer remains one of the most common cancers in Germany and is one of the leading causes of cancer-related deaths. In Germany, women and men aged 50 and older can choose between two colorectal cancer screening options: an immunological fecal occult blood test (FIT) every two years or up to two colonoscopies (preventive colonoscopies) at intervals of ten years. A colonoscopy is only necessary if the stool test is positive. Researchers led by Hermann Brenner from the DKFZ have now investigated the long-term effects of these options using an established simulation model.
Up to 80 percent fewer colorectal cancer deaths
The results show that if screening services are used consistently, up to three-quarters of all colorectal cancers can be prevented. The number of deaths from colorectal cancer can even be reduced by more than 80 percent—regardless of whether screening is primarily done through stool testing or preventive colonoscopy. Particularly significant effects are achieved when both methods are combined in a sensible way, for example, colonoscopies in younger years and supplementary stool tests in older age.
“Our analyses show very clearly that both screening strategies are highly effective. The decisive factor is not so much which method is chosen, but that as many people as possible take advantage of screening,” says study leader Hermann Brenner from the DKFZ.
Informed decision and personal preference
The study emphasizes that people can make an informed choice: Preventive colonoscopy is more complex, but offers the advantage of directly detecting and removing precancerous lesions. The stool test is less invasive and easier to perform, but must be repeated more frequently. A colonoscopy is only necessary if the test result is positive. In terms of their effectiveness against colorectal cancer, both approaches are comparable when used regularly.
From the researchers' point of view, high participation in colorectal cancer screening is the decisive factor in further reducing the burden of disease in Germany. “If alternative options help motivate more people to undergo screening, this is a major benefit for cancer prevention and public health,” says Brenner.
In the current analysis, the researchers assumed maximum utilization of screening services in order to illustrate the maximum possible effects. However, Hermann Brenner emphasizes that the actual overall utilization of colorectal cancer screening in Germany lags significantly behind the participation rates achieved in countries such as the Netherlands, Denmark, and the US. “To achieve this, we need well-organized screening programs with repeated personal invitations and measures that make screening as easy as possible, such as sending stool tests directly to participants or offering colonoscopy appointments,” summarizes the prevention expert.
Dmitry Sergeev, Thomas Heisser, Michael Hoffmeister, Hermann Brenner: Colonoscopy versus fecal occult blood testing versus no screening – a comparative analysis of long-term effects
Dtsch. Ärzteblatt 2026, DOI: 10.3238/arztebl.m2025.0208
