Quantifying the utility of single nucleotide polymorphisms to guide colorectal cancer screening

Aim: To determine whether single nucleotide polymorphisms (SNPs) can be used to identify people who should be screened for colorectal cancer. Methods: We simulated one million people with and without colorectal cancer based on published SNP allele frequencies and strengths of colorectal cancer association. We estimated 5-year risks of colorectal cancer by number of risk alleles. Results: We identified 45 SNPs with an average 1.14-fold increase colorectal cancer risk per allele (range: 1.05-1.53). The colorectal cancer risk for people in the highest quintile of risk alleles was 1.81-times that for the average person. Conclusion: We have quantified the extent to which known susceptibility SNPs can stratify the population into clinically useful colorectal cancer risk categories.