4 November 2014
New research has examined the effect of personalised genetic risk information on uptake of colorectal cancer screening.
A modest sized US study of over 780 people looked at the impact of providing individualised genetic and environmental risk assessment (GERA) for colorectal cancer to people with average disease risk. Half of the participants were tested for methylenetetrahydrofolate reductase gene (MTHFR) polymorphisms (the genetic risk measure) and serum folate levels (the environmental measure) that have been linked with a moderately increased risk of colorectal cancer. Based on this they were told that they had either average of elevated risk.
Six months on, the rates of screening uptake were not significantly different between the group who received GERA and the control group who did not. Within the GREA group, screening uptake was actually slightly lower among people who had been told their risk elevated than those who were told their risk was average.
Writing in Annals of Internal Medicine, the researchers conclude that their findings call into question the efficacy of moderately predictive genetic risk assessment on favourable healthcare behaviours. An accompanying editorial notes that using genomic information to refine risk estimates should not be expected to motivate significant behavioural change, but rather ‘information to identify patients who are most in need of such screening and then rely on proven persuasion techniques to encourage patients to get screened’.
Genomic information can
undoubtedly refine cancer risk prediction and enable more accurate
targeting of screening to those at highest risk. However, it is perhaps not
surprising to learn that it doesn’t necessarily have any more effect on
individual behaviours than other forms of risk information.