Novel Common Genetic Susceptibility Loci for Colorectal Cancer

Area of Science:

• Genetics
• Oncology
• Epidemiology

Background:

• Genome-wide association studies (GWAS) have identified 42 loci linked to colorectal cancer (CRC) risk.
• Additional susceptibility loci may explain the remaining familial risk for CRC.

Purpose of the Study:

• To identify novel genetic variants associated with colorectal cancer (CRC) risk.
• To assess the contribution of these variants to familial risk and improve risk prediction models.

Main Methods:

• Conducted a large-scale GWAS in European descent CRC cases and controls, followed by replication in independent European and multiethnic samples (total n = 163,315).
• Utilized logistic regression and fixed-effects inverse variance weighted meta-analysis to identify significant variants.
• Examined the generalizability of findings across East Asians, African Americans, and Hispanics.

Main Results:

• Identified 11 novel variants associated with CRC risk, with nine independently replicating.
• These novel variants increased the explained familial relative risk for CRC by 14.7% (from 10.3% to 11.9%).
• A polygenic risk score identified 4.3% of the population with at least a twofold increased odds of developing CRC.

Conclusions:

• This study enhances understanding of the genetic architecture of colorectal cancer (CRC).
• The identified variants and improved polygenic risk score can aid in developing individualized screening strategies for CRC.