Personalizing colorectal cancer screening by lifestyle

Colorectal cancer screening reduces the incidence and mortality of cancer. However, many individuals undergo unnecessary examinations because they do not have cancer or precancerous lesions. Screening programs often employ a "one-size-fits-all" approach where the only utilized risk factor is age. This project aims to investigate whether information about lifestyle can be used to personalize colorectal cancer screening according to participants' risk profiles.
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The development of colorectal cancer can be influenced by lifestyle factors such as smoking, high alcohol consumption, physical inactivity, obesity, and an unhealthy diet. Colorectal cancer screening reduces the incidence and mortality of this type of cancer. However, screening also leads to many individuals undergoing unnecessary examinations because they do not have cancer or precancerous lesions.

The screening test in the national colorectal cancer screening program is a fecal occult blood test, which is repeated every two years. Those who test positive for blood in their stool are invited to undergo a colonoscopy examination of the colon and rectum, which can detect cancer or precancerous conditions.

Personalized colorectal cancer screening that takes into account the participant's risk profile, including lifestyle, has the potential to reduce the number of unnecessary examinations and make the screening program more efficient. This could involve less frequent tests for those at low risk but closer monitoring and the appropriate test for those at high risk. Additionally, personalized screening can be used to improve the lifestyles of participants, thereby reducing the risk of colorectal cancer and other lifestyle-related diseases.



In this research project, we have investigated how to improve colorectal cancer screening programs to be better tailored to the participant's risk profile. We have also explored ways to improve the lifestyle of participants. This has been examined and developed in five sub-projects:

1. The relationship between lifestyle factors and the detection of colorectal cancer or precursors in the third and fourth screening rounds using fecal occult blood tests.

2. The association between lifestyle and the types of precursors to colorectal cancer.

3. Collaboration with the Department of Nutrition, University of Oslo, to develop an electronic questionnaire for effective assessment of the lifestyle of screening participants.

4. Testing the validity of the electronic lifestyle questionnaire.

5. The relationship between lifestyle, endoscopic screening, and precursors to colorectal cancer in two large American studies, in collaboration with Harvard University in Boston.