ABSTRACT
Objective: To evaluate the effectiveness of a risk-adapted colorectal cancer screening strategy constructed utilizing genetic and environmental risk score (ERS). Methods: A polygenic risk score (PRS) was constructed based on 20 previously published single nucleotide polymorphisms for colorectal cancer in East Asian populations, using 2 160 samples with MassARRAY test results from a multicenter randomized controlled trial of colorectal cancer screening in China. The ERS was calculated using the Asia-Pacific Colorectal Screening Score system. Logistic regression was used to analyze the association between PRS alone and PRS combined with ERS and colorectal neoplasms risk, respectively. We also designed a risk-adapted screening strategy based on PRS and ERS (high-risk participants undergo a single colonoscopy, low-risk participants undergo an annual fecal immunochemical test, and those with positive results undergo further diagnostic colonoscopy) and compared its effectiveness with the all-acceptance colonoscopy strategy. Results: The high PRS group had a 26% increased risk of colorectal neoplasms compared with the low PRS group (OR=1.26, 95%CI: 1.03-1.54, P=0.026). Participants with the highest PRS and ERS were 3.03 times more likely to develop advanced colorectal neoplasms than those with the lowest score (95%CI: 1.87-4.90, P<0.001). As the risk-adapted screening simulation reached the third round, the detection rate of the PRS combined with ERS strategy was not statistically different from the all-acceptance colonoscopy strategy (8.79% vs. 10.46%, P=0.075) and had a higher positive predictive value (14.11% vs. 10.46%, P<0.001) and lower number of colonoscopies per advanced neoplasms detected (7.1 vs. 9.6, P<0.001). Conclusion: The risk-adapted screening strategy combining PRS and ERS helps achieve population risk stratification and better effectiveness than the traditional colonoscopy-based screening strategy.