Risk adapted prevention strategies for colorectal cancer

Interventions: Group 1: Persons without family history of colorectal cancer: to fill out online-questionnaire Group 2: Persons with family history of colorectal cancer: to fill out online-questionnaire, take part in consultation regarding colorectal cancer prevention and donate the biosamples Primary outcome(s): The aims of the RaPS study are: 1. To provide the necessary empirical evidence for the design and implementation of efficient risk adapted CRC (colorectal cancer) screening strategies among the high risk group of people with family history of CRC. 2. To identify and evaluate novel biomarkers for noninvasive risk stratification and early detection of CRC and its precursors among people with family history of CRC. Study Design: Allocation: ; Masking: ; Control: ; Assignment: ; Study design purpose: prevention