People with a high polygenic risk score for colorectal cancer could benefit more at preventing the disease by leading healthy lifestyles than those at lower genetic risk, according to a study ‘Healthy lifestyles, genetic modifiers, and colorectal cancer risk: a prospective cohort study in the UK Biobank’, by Vanderbilt researchers published in the April issue of the American Journal of Clinical Nutrition.
Using data from 346,297 participants in the UK Biobank, the researchers determined the lifestyle scores of unhealthy, intermediate and healthy according to waist-to-hip ratio, physical activity, sedentary time, processed and red meat intake, vegetable and fruit intake, alcohol consumption and tobacco use. Polygenic risk scores are used to measure genetic susceptibility to colorectal cancer.
Vanderbilt researchers constructed polygenic risk scores using genetic variants associated with colorectal cancer risk identified in recent large genetic studies including more than 120,000 study participants. They also constructed polygenetic risk scores for several other common cancers in research, ‘Evaluating the Utility of Polygenic Risk Scores in Identifying High-Risk Individuals for Eight Common Cancers’, published in 2020 in JNCI Cancer Spectrum.
The researchers estimated that maintaining a healthy lifestyle was associated with a nearly 40% reduction in colorectal cancer risk among those with a high genetic risk of developing the disease. The percentage dropped to only about 25% among people at a low genetic risk for this cancer. People with a high genetic risk and an unhealthy lifestyle were more than three times as likely to be diagnosed with colorectal cancer than those with a low genetic risk and a healthy lifestyle.
"Results from this study could be useful to design personalised prevention strategies for colorectal cancer prevention," said Dr Wei Zheng, Anne Potter Wilson Professor of Medicine and associate director for Population Sciences Research at Vanderbilt-Ingram Cancer Center (VICC).
The published study in The American Journal of Clinical Nutrition is one of the few that quantifies potential interactions of overall lifestyle with genetic susceptibility to colorectal cancer.