[Screening for colorectal cancer. Current evidence and novel developments]

Colorectal cancer is one of the leading causes of cancer-related morbidity and mortality. Screening has been demonstrated to reduce both the incidence and mortality of colorectal cancer. In addition to the large group with a normal risk level, two further risk groups need to be distinguished: increased family risk and hereditary colorectal cancer syndromes. STANDARD METHODS FOR SCREENING: The highest evidence for all screening tests has been demonstrated for guaiac-based fecal occult blood testing. Colonoscopy is a diagnostic and therapeutic tool and it serves as the reference standard for other tests in clinical studies.

Fecal immunochemical tests have a higher sensitivity than guaiac-based tests. Several novel techniques are under development and could be adopted by screening programs in the future. Next to colonoscopy, computed tomography (CT) colonography and colon capsule endoscopy have the highest sensitivity for colorectal neoplasia. Molecular tests which are based on the detection of genetic and epigenetic changes of DNA released by the tumor into feces or blood have a high potential and could potentially replace occult blood tests in the future.

Colonoscopy is the primary instrument for screening for colorectal neoplasia. Fecal occult blood testing should only be performed if colonoscopy is denied and CT colonography has not yet been approved for screening in Germany.