The path to prevention
By Edward Weinman
The future has arrived. That’s good news for Amy Doneen, a nurse practitioner at the Heart Attack and Stroke Prevention Clinic in Spokane, Washington.
‘We now have one more tool in the tool belt,’ says Doneen, whose work at the clinic is geared towards, as the name suggests, preventing patients from suffering from heart attacks, stroke and diabetes.
The tool Doneen has added to her tool belt is deCODEme, a genetic screening test conducted by deCODE genetics. The deCODEme test, which requires patients to simply swab saliva from the inside of their cheek and then send it off to deCODE for DNA analysis, scans an individual’s genome for genetic markers linked to 36 different diseases, such as heart disease and Type 2 diabetes.
‘We’ve been aware of genetics and it’s value in medicine for a long time,’ says Doneen, whose Spokane clinic has been working with nutrigenomics (the effects of nutrition on genes) to help individualize care for her patients for over ten years. ‘But now we have the ability to test someone’s genetic risk for certain disease states and then make clinical decisions based on that genetic backdrop.’
‘It’s an exciting time,’ she adds.
What makes the genetic test so exciting is how after viewing a patient’s results, Doneen can zero in on that patient’s potential vulnerabilities, therefore helping shape that patient’s individual care.
‘The goal is to find out what path a patient is on to developing certain diseases and kick them off that path,’ Doneen says from her Spokane office.
The youngest patient Doneen sees is a 14-year old. (Let’s call her Jordan to protect her privacy.) Jordan’s genetic scan indicates that she has an inherited risk factor of developing Type 2 diabetes that is 27 percent greater than the general population. According to Doneen, this doesn’t mean Jordan will get the disease. However, after viewing Jordan’s disease panel, Doneen can set Jordan on a path to prevention by alerting her to possible diet restrictions to lower her lifetime risk.
‘It allows me to set screening guidelines and make appropriate health-related decisions for a lifetime for that child.’
The road to prevention
One thing that makes the deCODEme genetic test so valuable is that the test can be used to help clinicians empower their patients to practice preventative care.
‘Preventative healthcare in America is not where it should be,’ says Doneen. ‘The survival of heart attacks has never been better. The cardiologists are fantastic and bypass survival rates have never been better. But as a preventive measure we need to do a better job. We spend about $49 billion on stroke care, and 50 percent of that is spent on patents in nursing homes.’
Finding out early that Jordan has a higher than normal inherited risk of developing Type 2 diabetes is vital. But why not just wait until she develops diabetes and then treat her?
‘Once you are diagnosed with Type 2 you are at the same risk for stroke or heart attack as someone who has already had a heart attack,’ Doneen says, revealing the importance of preventative care.
Today, doctors have a set of tools they use to monitor a person’s risk of Type 2 diabetes, the most prominent being the testing of fasting glucose levels. The problem with using only the current diagnostic tools is that, according to Doneen, glucose levels are the last characteristic to change. Once glucose levels signal Type 2 diabetes, a patient has had upwards of 20 years of vascular damage.
‘This is why deCODEme’s genetic test is such an important tool to help prevent disease. It’s one more opportunity to say, `Yes, you’re on this path to Type 2 now let’s do everything we can to kick you off that path,’’ she argues.
Genetic testing changes healthcare
DeCODE’s genetic test has the possibility to transform the way clinicians practice medicine. At the moment, doctors have certain diagnostic tools at their disposal to help evaluate patients. These tools are then applied to certain general population studies to help evaluate risk. For example, a doctor can take a patient’s Body Mass Index or BMI, combine that with age, gender, whether or not you smoke, and put it into a calculation that spits out a number which reveal an ‘x’ percent risk of suffering a heart attack in the next ten years. This is the essence of risk-factor analysis. Chasing numbers. But it’s limited.
‘All of these risk tests have a strong predictive value. If you fail your stress test or your Framingham score then you’re at high risk. But they have weak negative predictive value. In other words, if you pass them you might not be okay. Genetics look at lifetime risk, and help the clinician make decisions.’
To see how deCODEme’s genetic test changes the way doctors practice medicine, one need only look at Jason, one of Doneen’s patients. Jason (whose last name is not used to protect his privacy) has plaque build-up in his arteries, hypertension and high cholesterol. He also has a history of palpitations. The normal course of treatment is pills to lower his blood pressure, pills to lower his cholesterol and clean out his arteries. Doctors might also put Jason on a heart monitor for a week to evaluate if those palpations are A-fibrillation, abnormal beats or if they have a clinical significance of increasing Jason’s risk of stroke. Thankfully, Jason’s week-long heart monitor comes back negative.
‘Prior to genetic testing that was it. Close the book. We’re done. Let’s treat you for cholesterol, hypertension and plaque and assume we covered all our bases.’
But because Jason’s mother had a history of strokes, Doneen wanted to dig deeper. She used deCODEme’s genetic test and searched Jason’s genome for a gene that medical studies have related to A-fibrillation. Jason was positive for the A-fib gene, so despite the fact that his heart-monitor test was negative Doneen put him on a heart monitor, but this time for a month in order to be more accurate. Sure enough, the month-long test showed that Jason was going into a-fib. Doneen immediately started treating Jason with a different course of medicine.
‘The test changed his course of treatment,’ she says enthusiastically.
Doneen cautions that just because a patient has an abnormal gene doesn’t mean that patient should be treated with medicine. In fact, she says there is no evidence to treat patients based on an abnormal gene. However, knowing that Jason had this abnormal gene, and had a family history of stroke, Doneen decided to take action, and put Jason on a heart monitor, which fundamentally altered his clinical course.
Why not just put everyone on a heart monitor for a month, instead of a week, and therefore make sure patients don’t have a false negative test?
‘Putting everyone on a monitor for a month is not feasible. But putting someone who has an abnormal gene on a monitor, that’s feasible.’
Consumer driven
While the power of genetic testing is still in its infancy, deCODEme’s genetic test enables doctors to fine-tune their treatments to individuals much like a tailor takes clothes off the rack, and alters them to fit an individual’s unique shapes and curves.
‘Genetic testing allows you to step beyond that mean of the general population. Evidence based medicine and guidelines are made for the mean to a general population. But we don’t all fit into that box. So knowing someone’s genetic risk augments your decision path above and beyond what the guidelines recommend,’ says Doneen.
With the advances in genetic testing it’s apparent that the old standards and tests need to be enhanced. Proponents of genetic testing are not arguing that the old guidelines and diagnostic tools are outdated. But the future of healthcare is preventative care where treatment is shaped to fit an individual patient.
‘I want to be as individual in care as possible. I’m going to use all the evidence that’s out there and then use the genetic piece to say what’s unique about this individual that may determine a unique approach to their clinical decisions.’
But what about the cost? Is $1000 too much to pay for a genome scan?
‘The cost shouldn’t be a hurdle. It’s amazingly within reach. If you talk to people who had an event, either a heart attack or diabetes, they were out of work for six months or had a stent inserted for $30,000, the cost of deCODEme’s test becomes practical in the big picture.’
Living in the future
Genetic testing is just arriving to the market place, and many doctors are currently unaware of the clinical efficacy of scanning a patient’s genome for inherent risk of contracting certain diseases. As usual, science and consumers seem to be ahead of the curve. With the advent of the Internet, medical consumers are more savvy, and demanding more information about genetic testing. As Doneen points out, there are going to be a lot of clinicians that are going to be caught off guard when their patients begin asking about genetic testing.
Doctors need to bridge this knowledge gap. The concern is that if genetic tests are market driven rather than driven by clinicians, then some patients will be given information without education, and Doneen sees this as a problem.
‘The future of generics is real. It’s here. The clinical arena is going to become an essential part because genetic tests will now help to set screening guidelines, shape treatment decisions and shape clinical outcomes. It needs to be understood by clinicians. If both patient and clinician are educated then it becomes a huge clinical tool,’ Doneen claims.
If genetic tests are going to shape the future of medicine, and alter treatment programs, what should a patient do if their doctor shows resistance to genetic tests?
As Doneen suggests, find a new doctor.