Introduction: Individuals with a family history (FH) of colorectal cancer (CRC) are at increased risk of CRC and recommended to start screening earlier than the average-risk population. Current recommendations focus on FH and genetic predisposition, but don’t consider lifestyle-related risks.
Objective: To evaluate and compare risk factors for CRC precursors and predictors of risk perception among first-degree relatives of CRC patients aged 40-54 in Germany.
Methods: Data from 922 participants with a FH of CRC were analyzed in a multicenter, cross-sectional study. Participants completed questionnaires on sociodemographic and lifestyle factors, medical history and perceived CRC risk. Colonoscopy findings were categorized according to the most advanced lesion at colonoscopy. Multivariable logistic regression was used to assess predictors of both presence of neoplasms and CRC risk awareness.
Results: Two hundred twenty (23.9%) participants were found to have colorectal neoplasia, including 63 (6.8%) with advanced lesions. Strong associations with advanced neoplasia presence were observed for obesity (aOR 2.44, 95% CI 1.12–5.22), smoking (aOR 1.47, 95% CI 1.14–1.88/10-pack-years), and physical inactivity (aOR 2.51, 95% CI 1.11–5.25). However, these factors did not match the lifestyle predictors of perceived risk. Instead, alcohol consumption and fruit and vegetable intake were the lifestyle factors most strongly related to people’s sense of their own risk.
Conclusion: Our results show a significant disconnect between objective risk factors for colorectal neoplasia and participants’ risk perceptions. Individuals with a FH of CRC may benefit from tailored risk communication and personalized screening strategies incorporating lifestyle factors.