Background: Risk-based screening is a promising approach that could improve the risk-benefit balance of cancer screening. However, it has been shown that communicating individual risk alone has a low impact on screening behavior, and risk communication as a category (low, moderate, or high) may not be efficient. Indeed, informing participants they are at low risk may demotivate them from screening. High-risk category may cause anxiety and be contested by health professionals, as high-risk individuals are generally outside the organized screening programs. Moderate risk is ambiguous and does not allow strongly recommending any specific screening test. Finally, people with strong beliefs about their risk level may mistrust the communicated risk category. We believe that providing screening recommendations based on risk may help to overcome such drawbacks.

Objective: To refine our information brochure in order to improve participants’ understanding of colorectal cancer (CRC) risk and screening options, and to reduce barriers to screening.

Methods: This work is conducted in the framework of PRESENT-CRC, a multicenter randomized controlled trial carried out in Switzerland (Registration: ISRCTN10525659). The information brochure was first developed for our randomized controlled pilot trial (n=515) that aimed at assessing the feasibility of personalized screening in Switzerland. The brochure communicated general information about CRC and screening, 15-year risk for CRC as percentages, natural frequencies, and risk category (low, moderate, and high), as well as provided recommendations for screening methods based on risk. As it has been shown that risk-based screening does not increase overall participation, the main purpose of the brochure was reorienting participants to risk-appropriate screening methods. To adapt the brochure for PRESENT-CRC, we conducted interviews with five cancer screening programs participating in the trial and our citizen advisory group (n=5). We also used the responses from the pilot study follow-up questionnaire, which provided information about the barriers for screening.

Results: Both screening programs and citizens suggested removing risk categories as they were deemed confusing. High-risk category was particularly criticized and considered anxiety-inducing and incorrect, as high-risk individuals are not a part of organized screening programs in Switzerland. Therefore, the central message of the revised brochure for PRESENT-CRC is the screening recommendation with the risk information used as a justification. The brochure recommends a FIT to people having a risk between 0 and 3.9% and colonoscopy to those at risk of 4% and higher. In addition, we considered barriers for screening identified in the pilot study to improve our guidance on how to obtain screening services. We also emphasized that screening is intended for people without symptoms, as many pilot study participants believed it was needed only when health problems arise.

Conclusion:  Risk-based CRC screening requires clear, credible information and recommendations if participants are going to complete appropriate screening tests. Based on feedback, we chose to focus on recommended tests, while deemphasizing individual absolute risk and removing categories like high, moderate or low risk.