Direct-to-Consumer Personal Genome Testing and Cancer Risk Prediction

Abstract

The last several years has witnessed an explosion in genomics, with the advent of genome-wide association studies revealing hundreds of DNA variants significantly associated with most common diseases, including cancer. On the heels of these scientific advances came the direct-to-consumer (DTC) genetic testing industry. Genome-wide scans for disease have been marketed and sold directly to the public, without the involvement of a health care provider. Unlike genetic testing for mutations in known hereditary cancer susceptibility genes such as BRCA1/2, these genomic profiles examine DNA variants, which typically have a minimal risk impact, and account for only a fraction of the heritable component of cancer. Furthermore, risk information provided to consumers does not account for family history or other known risk factors. The clinical validity and utility of personal genome scans for disease risk prediction remain for the most part unestablished, although some argue lack of evidence of harm and the possibility that positive impacts on health behaviors or genetic awareness may result from consumer use. The DTC genetic testing industry has sparked significant controversy not only among the scientific community, but also among professional societies and government agencies.In this review, we present some of the history and methodological considerations of DTC genomic profiling, with a focus on cancer risk prediction. The literature regarding consumer awareness and utilization is explored, including understanding, expectations, and behavioral and psychological responses to DTC genomic risk prediction. Primary care provider and genetic professional knowledge and perceptions of DTC genomic profiling are also addressed. Ethical and scientific controversy surrounding the DTC genetic testing industry is presented, along with policy recommendations, regulatory actions, and the changing landscape of the DTC genetic testing market in response. Although our understanding of the human genome holds much promise in the realm of cancer prevention and treatment, DTC genomic profiling for cancer risk prediction is unlikely in its current form to have any significant impact on the health of the public. Time will tell if the next venture in genomic medicine, whole genome sequencing, will be accompanied by the translational research and emphasis on public/provider education required to ensure its successful application toward reducing the burden of cancer at a population level.