Genetic Testing in Treatment Decision Making Goes Mainstream

When the human genome was finally sequenced by the National Human Genome Research Institute (NHGRI) and the International Human Genome Sequencing Consortium in 2003, many thought it would bring a brave new world of medicine. But between the great expense of sequencing and the challenges of understanding the clinical relevance of different gene variants present in an overwhelming amount of data, medical genomic applications have lagged more than originally expected.

That said, Teri Manolio, MD, PhD, director of the NHGRI’s division of genomic medicine says the healthcare industry may be reaching a tipping point. Between consumer genetic testing kits like 23andMe becoming more popular, and more research studies pinpointing how genetics can inform both diagnosis and treatment, she believes we are only beginning to see genetic testing’s true potential at the bedside.

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“The technology is improving rapidly, becoming not only more accessible but much, much cheaper,” she says. “And as genetic tests are increasingly used, we know much more about how to apply them. These two trends are building on themselves, making it these kinds of tests are, more and more, being used to help inform treatment decisions.”

Cancer leading the way

Manolio says that heritable cancers have led the way to making genetic testing more mainstream-certainly tests for BRCA1 and BRCA2 mutations, genetic variants linked to aggressive breast and ovarian cancers, have become part of the popular medical lexicon. In fact, earlier this year, CMS announced it would cover Next Generation sequencing tests for cancer patients. But Robert Epstein, MD, MS, chief executive pfficer and president of EpsteinHealth, LLC and an adjunct assistant professor of health economics at the University of Southern California, says that research studies have demonstrated that genomics can offer enhanced diagnostics across a variety of conditions-not just cancer.

“The last 20 years of research have borne out some concrete and disruptive applications for medicine,” he says. “Cancer genetics have certainly driven a lot of that innovation. But we also see blood tests that can screen for genetic conditions of the fetus during pregnancy, tests to screen for diseases in newborns, and tests that can help diagnose rare diseases.”

Many of these applications, Epstein says, have been approved by the FDA-and insurance companies and health plans are willing to pay for them. While most of these genetic tests offer doctors the ability to identify medical conditions early, thus offering the potential for lower healthcare costs and better patient outcomes, there are also new opportunities to inform treatment selection and the management of chronic medical conditions. Pharmacogenetics, or the use of genetic testing to inform how an individual patient will respond to drug treatment, can help doctors choose the right medications for patients without having to resort to trial and error prescribing.

“The clinical utility of these tests is being demonstrated,” he says. “And with patients being so much more open to having their genome sequenced, it’s getting out there. We will be seeing it used more often in primary care in the future.”

Theory into practice

Such tests are already being used in the present. After piloting an innovative program called MyCode-a precision medicine project that included genetic testing-Geisinger, a combination health system and health plan based in central Pennsylvania, rolled out clinical sequencing as part of routine care for their health plan members. Erica Ramos, director of clinical and business development at Geisinger National, says they are hoping to show the rest of the nation the true value of genetic testing in primary care.

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“When we looked at our data, we saw that 88% of the MyCode patient participants who had received genetic testing with actionable results would not have been identified otherwise,” she says. “That’s in an institution with extensive experience and expertise in genomics. That tells us that it’s challenging to pick up people who are risk for these diseases unless you are really casting a wide net.”

Geisinger has carefully selected the specific genes and diseases to screen for, highlighting those with a strong evidence base. Those conditions include hereditary cancers, cardiac disorders, and rare disorders like connective tissue disease. Ramos says, since they’ve started the program, approximately 2% to 3% of patient tests have come back with actionable results.

“It’s a manageable number,” she says. “We wanted to dial into the conditions where we can have the most medical impact.”

Geisinger is still collecting data on how the new program is influencing the quality of care, as well as its effect on medical and pharmacy costs, but Ramos is optimistic that they will see significant benefits.

“By implementing genetics, it’s not always about huge changes in management and care-although it certainly can be,” she says. “It’s really about tweaking the care of people who have these medical risks to make sure their care is optimized. That’s the goal of personalized medicine. And, over time, we believe we will see a good return on that investment.”

Where does testing go from here?

Ramos is part of Geisinger’s National Precision Health Effort, working to help other health systems and health plans across the country to educate them on the benefits of genetic testing-and to help them find ways to adopt them into routine healthcare. She believes that in a year or two, due to patient and provider demand, more health plans will not only grudgingly reimburse genetic tests for certain conditions, but heartily endorse them as part of primary care.

While there are some barriers to adoption-perhaps most glaringly a lack of genetic testing counselors to work with primary care providers to help explain test results-Manolio is optimistic that genetic testing is coming into its own. It may not be what was imagined in 2003-but it has a great potential to help providers make sound, effective clinical decisions for patients across a variety of health conditions.

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“By getting the exome or genome sequence first, before any diseases have been diagnosed, providers can intervene early and make a difference,” she says. “The alternative is waiting until years have passed, hundreds of thousands of dollars in medical tests have been done, and patients are in a place where it is harder to turn things around. More and more, medical systems are going to recognize this is a way to distinguish themselves from their peers and offer their patients the highest quality healthcare.”

Kayt Sukel is a science and health writer based outside Houston.