Colorectal cancer screening based on predicted risk: a randomized controlled trial.

Introduction: Colorectal cancer (CRC) screening relies primarily on colonoscopy and fecal immunochemical testing (FIT). Aligning utilization of these options with individual CRC risk may optimize benefit with lower risks, individual burden, and societal costs. We studied the effect of communicating personalized CRC risk and corresponding screening recommendations on risk-appropriate screening uptake in an organized screening setting.

Methods: Randomized controlled trial among residents aged 50-69 years not yet invited for screening in Vaud, Switzerland. The intervention was a mailed brochure communicating individual 15-year CRC risk and screening recommendation. The control group received a usual brochure comparing FIT and colonoscopy. The primary outcome was self-reported risk-appropriate screening (FIT if <3% risk, FIT or colonoscopy if ≥3% and <6%, colonoscopy if ≥6%) at 6 months. A secondary outcome was overall screening uptake.

Results: Of 5396 invitations, 1059 people responded (19%), of whom 258 were randomized to intervention and 257 to control materials (average 15-year risk 1.4% (SD=0.5), age 52.2 years (SD=2.2), 51% women). Risk-appropriate screening completion was 37% in the intervention group and 23% in the control group (absolute difference 14%, 95%CI 6%-22%). Overall screening uptake was 50% in the intervention and 49% in the control group (absolute difference 1%, 95CI -7%-10%).

Conclusions: In a population not known to be at elevated CRC risk, brochures providing personalized CRC risk and screening recommendations improved risk-appropriate screening without impacting overall screening uptake. This approach could be helpful for aligning screening methods, risks, and benefits with cancer risk and resource allocation.