N16: Colorectal Cancer Risk Susceptibility Loci In A Swedish Population

W. Liu, H. Mahdessian, X. Jiao, A. Lindblom

Karolinska Institutet


Aim: Around 30% of all colorectal cancer has a genetic contribution. Less than 5% have an inherited mutation in a known high-risk colorectal cancer (CRC) gene.  A germline mutation in cancer predisposing genes is known to increase the risk of more than one tumor type. In order to find loci associated with CRC,  a genome-wide association study (GWAS) was conducted.

Method: The study used haplotype analysis instead of single SNP analysis in order to find putative founder effects. Logistic Haplotype association studies  was conducted. 2,637 Swedish CRC cases and 4,780 healthy controls were analyzed for 219,114 SNPs.

Results: Logistic Haplotype association studies identified three risk loci associated with CRC risk, on chromosomes 2q24.2 (OR= 0.45 and p= 1.59 x10-9), 2q14.3 (OR= 0.61 and p= 9.39 x10-9)  and 16q23.3 (OR= 2.77 and p= 1.10 x10-9). Some of the candidate loci hold several cancer genes, suggesting that the risk associated with one locus could involve more than one gene associated with CRC risk.

Conclusion: In summary, this study identified three novel candidate loci associated with CRC risk. It was also suggested that cancer risk at one locus could depend on multiple contributing risk mutations/genes.