By Joel Diamond, MD, FAAFP
As it has evolved, the clinical application of genetic/genomic testing has skipped over an important stakeholder group: primary care providers (PCPs).
For decades, genetic/genomic insights have found a home in multiple specialty and subspecialty areas including oncology, maternal fetal medicine and rare disease. And, more recently, consumers – also known as patients – have embraced the clinical value of genetics and genomics, thanks to FDA approval of tests offered by entities like 23andMe and Ancestry.com.
Granted, there are logical explanations as to why PCPs have been left out of the loop. Genomic science has largely been driven by research efforts with findings applied in advanced academic settings for the treatment of hard-to-manage conditions. The growth of consumer adoption has been fueled by commercial – as opposed to clinical – interests of testing entities. Finally, few PCPs received in-depth training about how to incorporate genetic data into clinical decisions during their education, now years or decades in the past.
But growth of, and interest in, genetics/genomics has reached critical mass. Caught between advancing science and patient demand, PCPs are actively seeking strategies and tools to harness the power of precision medicine, typically in one (or more) of three areas:
1Identifying patient risk for heritable conditions.
Clearly, PCPs cannot test every patient for everything, but capturing a clear family history using advanced pedigree tools within powerful precision medicine solutions enables PCPs to more easily identify patients where genetic susceptibility may exist and refer them for germline testing. Science has already discovered that genetic factors impact more than 6,000 diseases. Providers have long accepted that BRCA1/2 testing helps pinpoint risk for breast, ovarian and additional cancers. Other molecular tests can likewise inform PCPs about conditions they commonly treat. For example, genetic testing among patients with ancestors who died suddenly from unexplained cardiac events might reveal the individual carries a mutation for long QT Syndrome or dilated cardiomyopathy. Discovering these factors allows PCPs to initiate preventive measures, along with aggressive screenings. If the patient ultimately develops the disease, the PCP is likewise well equipped for early intervention, appropriate referrals and highly targeted treatment.
2Improving medication safety.
Healthcare has made great headway in improving medication safety. Quality improvement programs have helped us identify and monitor drug-drug interactions and patient medication allergies. Drug-gene interactions identified through pharmacogenomic testing (PGx) are the next challenge to tackle. It is estimated that 18 percent of all prescriptions written may be impacted by patient genetics, and that 34 percent of all adverse drug responses are likewise attributable to PGx factors. Nor is safety the only issue; PGx factors impact drug efficacy as well. Patients who metabolize a specific pain medication too quickly, for example, will not experience relief from a standard dosage because their bodies process it too quickly. Interestingly, a great number of the medications with pharmacogenomic indications are used to treat common conditions seen by PCPs in the course of an ordinary visit: depression, anxiety, high cholesterol, pain, post-surgical bleeding and more.
3Achieving therapeutic benefit sooner.
Besides determining patient risk, germline testing also enables PCPs to arrive at a precise diagnosis faster and initiate treatment more quickly. For example, genetic testing of congestive heart failure patients may uncover inherited dilated cardiomyopathy. This is an important distinction that allows the physician to make the best treatment decision for the patient, but also enables communication about risk to other family members.
Ultimately, results from genetic/genomic testing represent nothing more than additional information a PCP can use during clinical decision making – and very few argue that more information is a bad thing. A PCP’s mission, after all, is to keep patients healthy whenever possible and, when they become ill, to diagnose them accurately and treat them as effectively and quickly as possible. Precision medicine gives providers another tool to achieve their objectives. Fully integrated and actionable within the clinical workflow, genetic and genomic results help PCPs become even better at fulfilling their mission – leading, in turn, to better outcomes, higher quality and improved patient satisfaction.
Joel Diamond, MD, FAAFP, is an Adjunct Associate Professor of Biomedical Informatics at the University of Pittsburgh. He is a diplomat of the American Board of Family Practice and a fellow in the American Academy of Family Physicians. He cares for patients at Handelsman Family Practice in Pittsburgh and serves as Chief Medical Officer for 2bPrecise.