Personalized medicine — using genomic information to inform medical treatment decisions — is no doubt the future of healthcare. Having a patient's detailed genetic information and using it to inform clinical decision making will reduce diagnostic error and improve treatment effectiveness, as treatments can be tailored and selected for certain genetic markers or variation.
Whole genome sequencing, the most advanced form of genetic testing, has been on the rise, due in part to the fact the cost of WGS has dropped significantly in the last decade, to around $1,000 today — an affordable price for patients with rare or complex diseases who desire the most advanced treatments available. However, the path to this future state of personalized medicine may be a long and windy one, at least according to the findings from a JAMA study released yesterday.
The JAMA study by Dewey et al. followed 12 adults who underwent WGS at Stanford University Medical Center between November 2011 and March 2012, and set out to examine how the findings of WGS could or would impact the patients' clinical care.
Patients, of course, expect that undergoing WGS will "uncover genetic findings of potential clinical importance," according to a JAMA news release on the study's findings. Yet, the Stanford study reveals patients' expectations may be higher than current genomic interpretation will allow.
According to the study, WGS was "associated with incomplete coverage of inherited disease genes, low reproducibility of detection of genetic variation with the highest potential clinical effects, and uncertainty about clinically reportable findings." To say it simply: The known variations that are most linked to clinical conditions were not always identified, and experts didn't always agree on the variation present. Plus, the manpower required to analyze the variation was costly (about $15,000 per patient). Given the unreliable findings, the results may not be worth the cost, said the study's authors.
The researchers did find one woman with the BRCA1 gene but no family history of breast or ovarian cancer. Thus, they specified, in certain cases, "WGS will identify clinically actionable genetic variants warranting early medical intervention.
The findings suggest that despite the technological advancements for genome sequencing in the last 10 years, the clinical applications aren't yet ready for primetime. This doesn't mean they won't be soon, and perhaps the JAMA study's findings will light a fire under DNA researchers to better understand variations with clinical implications, and the depth of those implications. While the study itself highlights a number of current problems with relying on WGS to guide clinical decision making today, the potential of genomic information to guide clinical decisions is no less powerful. As Gregory Feero, MD, PhD, a senior advisor at the National Human Genome Research Institute, wrote in a JAMA, "Ideally, uncertainly in medical decision making would be reduced and clinical outcomes improved by making interpreted genome-sequence information available to patients, physicians, and other practitioners. This is a major premise of the movement to personalized or precision medicine."
The full premise of personalized medicine isn't yet realized, but the foundation exists. The brilliance of researchers, paired with the desire of clinicians for better ways to help treat their most complex of patients, suggests that the future state is attainable, it just needs time.