Non-invasive markers for colorectal cancer screening.

Interventions: Collection of blood and fecal samples (once). Non-invasive markers for colorectal neoplasia will be determined in blood, feces and tissue. All combinations of markers will be tested in order to optimize the diagnostic accuracy for colorectal neoplasia, considering the outcome of colonoscopy as the gold standard. In addition the results of the non-invasive markers in patients at high-risk will be compared with the results of an average-risk population, in order to identify risk factors. Primary outcome(s): Diagnostic accuracy of molecular and protein markers in screening for colorectal neoplasia in subjects at high-risk for CRC and CRC patients, in comparison with average-risk subjects. Study Design: Non-randomized controlled trial, Open (masking not used), N/A , unknown, Parallel