Personalised Risk Assessment Fails to Encourage CRC Screening

Individualised genetic and environmental risk assessment does not increase adherence to colorectal cancer screening

medwireNews: Knowledge of personalised genetic and environmental risk information does not increase the uptake of colorectal cancer (CRC) screening in individuals at average risk of developing the disease, research shows.

Participants nonadherent to screening recommendations were randomly assigned to receive either a genetic and environmental risk assessment (GERA; n=514) that determined whether their risk of CRC was “average” or “elevated” or usual care (n=269).

The results of the risk assessment, which involved analysis of the methylenetetrahydrofolate reductase (MTHFR) Genotype and serum folate levels, were communicated to each participant by a trained nurse, say David Weinberg, from Fox Chase Cancer Center in Philadelphia, Pennsylvania, USA, and colleagues.

Individuals with low folate levels who carry specific variants of MTHFR are thought to have a 1.5 to 2.0 fold increased risk of CRC, they explain.

Even though both intervention and control group participants were encouraged to undergo screening, the team reports in the Annals of Internal Medicine that the CRC screening rates were similar in both groups, at 33.1% in the GERA versus 35.7% in the usual care group, with an odds ratio of 0.89.

Jennifer Blumenthal-Barby, from Baylor College of Medicine in Houston, Texas, USA, and co-authors comment in an accompanying editorial that the combination of an individualised risk assessment and counselling was reasonably expected to increase CRC screening, but it did not, making this an important negative trial that highlights the limits of relying on risk information alone to modify patient behaviours.

There was also no significant difference in screening uptake at 6 months within the GERA group when the participants were stratified by risk. Interestingly, the screening rates were higher in participants with an average risk than in those with elevated risk (38.1 vs 26.9%), although the difference was not significant.

“Research has shown that the same numerical risk feels higher to persons when it is described as being above average”, write the commentators. But they add that “in this study, participants were unmoved by the news of their above-average risk, which is an important negative result.”

They point out that perhaps the key is to use personalised risk information to identify patients who most need screening, and then use proven persuasion techniques to encourage them to undergo screening.

David Weinberg and co-workers conclude: “The role of genetic and molecular testing to predict response to specific therapeutic options in health care delivery is increasing; however, the potential for similar testing to motivate behavioral change is less clear.”


Weinberg D, Myers R, Keenan E, et al. Genetic and environmental risk assessment and colorectal cancer screening in an average-risk population: a randomized trial. Ann Intern Med 2014;161: 537–545 doi:10.7326/M14-0765

Blumenthal-Barby J, McGuire A, Ubel P. Why information alone is not enough: behavioral economics and the future of genomic medicine. Ann Intern Med 2014;161: 605–606 doi:10.7326/M14-2074

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