Background: Although some smokers seem interested in obtaining personal lung cancer risk information based on genetic testing for common genetic variants, it is unclear whether or how they understand the predictive power of these tests prior to decision-making. Young smokers are a particularly important group to consider because they are even more likely than other smokers to engage in optimistic biases about their disease risks. We, therefore, assessed how young smokers interpret information about genetic testing for a common lung cancer-associated genetic variant, and whether perceived magnitude of risk conferred by the variant predicted interest in testing.
Methods: Participants (128 smokers recruited at a university) read information about genetic testing for a common lung cancer-associated genetic variant, including that the adverse genotype increased lung cancer risk by about 20%, and that the absolute lung cancer risk was about 11% (`higher risk' genotype) versus about 9% (`lower risk' genotype). We assessed risk interpretation in 2 ways.
Results: On the 5-point measure of risk interpretation, most participants (89%) reported that the genetic variant `increases risk a little.' On the 7-point measure, over a third perceived it to increase risk `a moderate amount' (34%). Interest in testing was quite high (mean = 5.2 on 7-point scale), and was not associated with interpretation of disease risk conferred by the gene variant.
Conclusions: The findings contribute to growing evidence that some young smokers appear interested in personal genetic risk information even when the predictive power is low. The finding that a significant proportion of young smokers interpreted a relative risk of about 20% as `a moderate amount' challenges current assertions in the genomics community that common variants associated with risks of this magnitude have little to no meaning to individuals.