Novel Method in Colorectal Cancer Risk: Polygenic Risk Scores

In a ground-breaking turn of research, a team of researchers at the University of Helsinki have discovered a novel method of assessing the risk of colorectal cancer. By analyzing genetic data and health records of over 450,000 Finns, they were able to construct polygenic risk scores for this common yet deadly disease. The results of this study, published in the British Journal of Cancer, has significant implications for the future of colorectal cancer screening and early detection.

Understanding Polygenic Risk Scores

The polygenic risk score is a measure of an individual’s genetic predisposition towards developing a disease. In the case of colorectal cancer, the study found that individuals with the highest polygenic risk scores were almost four times more likely to develop the disease than the average population. Dr. Nina Mars, the senior author of the study, pointed out that most people diagnosed with colorectal cancer do not have a family history or other strong risk factors, making this development critical for early detection.

Implications for Colorectal Cancer Screening

The study suggests that these polygenic risk scores could be used to determine the optimal age to start screening based on an individual’s inherited risk. This could potentially increase the effectiveness of early detection efforts and reduce mortality rates. Finland, which began non-selective screening approaches for individuals aged 60-68 in 2022, with plans to expand to ages 56-74, could significantly benefit from this risk assessment tool.

Future of Genetic Risk Assessment

The study underscores the potential for genetic risk information to improve early detection and screening methods for colorectal cancer, a disease whose incidence is on the rise both in Finland and globally. The polygenic risk scores could also aid in assessing the risk of colorectal cancer post-colonoscopy, thus identifying high-risk individuals who could benefit from earlier follow-up. While this research is encouraging, further studies are needed to establish the efficacy of risk-based screening and to address the predominantly European ancestry of existing PRSs.