How to get the most out of precision medicine

Precision medicine and genomics hold great promise for the future of medicine. Harnessing this incredible opportunity to improve the quality and specificity of care will depend on a thoughtful and effective understanding of what it can and can’t do for patients. We must also address how to deploy new evidence-based testing and technology quickly and efficiently, providing the maximum value for patients while minimizing potential health disparities and harm.

Precision medicine includes an emerging array of genetic test results to inform decision-making on the prevention, diagnosis and treatment of disease. Since the completion of the human genome project, the ability to sequence an entire genome or specific exomes has dramatically improved, from both a scientific and cost perspective. In 2013, 62,000 variants in the human genome were identified that relate to human health. As of 2018, that number has grown to 850,000. Additionally, in 2017, the testing market was growing at a rate of 10 new tests every day, with 70,000 retail tests currently on the market. Despite this rapid growth, there is still sizable uncertainty as to how to use these newly developed tests in clinical practice.

Kaiser Permanente recently performed a survey about clinician attitudes towards precision medicine. More than 1,500 physicians responded to the survey. They indicated the importance of integrating the key actionable findings from genomic testing into population-based management tools, including routine cancer screening and maintaining high levels of blood pressure and blood sugar control.

Three priorities for precision medicine in America

For the United States, the Centers for Disease Control (CDC) has identified three priorities (the CDC3) for prevention using precision medicine tools: Lynch syndrome (colon cancer), hereditary breast and ovarian cancer, and familial hypercholesterolemia - a genetic condition which leads to high levels of 'bad' cholesterol in the blood.

These provide immediate opportunities to apply precision medicine in patient populations. This includes screening populations with precision medicine tools; creating registries and/or tracking systems for timely follow-up care; sharing decision support tools with patients and clinicians; and engaging patients through online care plans and reminders. In essence, the management of these three groups of patients is in many ways similar to the management of any other set of patients with a chronic disease or with a need for chronic testing or management. These three diseases represent evidence-based uses of precision medicine that should be implemented rapidly.

One challenge with precision medicine is that despite the advances in genomic testing, a good family history is still important to know which patients to test and how to identify family members of patients with a genetic disease. Currently, most electronic medical records do not make this easy to do in a busy clinical practice. We’re evaluating online family history collection and automated risk assessment tools to increase our identification of patients who may be at risk for these hereditary conditions, beginning with hereditary breast and ovarian cancer (HBOC). For those who may benefit from genetic testing, we’re looking at alternative models for educating, counseling and testing patients to improve patient satisfaction and genetic counseling capacity.

Based on genetic test results reaching back to the early days of testing, we are developing a national registry of our patients who have tested positive for HBOC. By leveraging existing population health tools and systems, we are developing ways to track care plans, surgical consults, interventions and screenings, and to implement automated notifications and follow-ups to ensure that patients receive the care they need. Our goal is to use the systems developed and lessons learned to create cross-specialty approaches for risk assessment, testing, registry and tracking for the CDC’s three priority conditions. These systems can serve as the foundation of expected expansion of sound uses of genetic testing to improve the health of the populations we serve.

At the same time, it’s important to understand that precision medicine isn’t just about genomics. There are other types of “omics” that inform patients’ health and how to tailor treatments to the individual. These include social determinants of health, exercise as a vital sign, lifestyle factors and others. “Exposomics”, for example, are the effect of environmental or occupational exposures over a person’s lifespan. We have reported in our Adverse Childhood Experiences study how early childhood traumatic experiences can have a large impact on health during later adulthood.

Promise - and discipline

As physicians and industry leaders, we must temper the promise of precision medicine with discipline about how we use it. Although using precision medicine for the CDC3 appears warranted, we have less clarity about its various uses in other areas of medicine. One method to gain more insight as to what works includes conducting appropriate research - preferably in a real world setting to maximize generalizability - to understand better the uses of new approaches.

We need to encourage multi-institutional collaborative studies and transparent data sharing. Research aimed at understanding the benefits of precision medicine for both developed and developing nations should be a priority. Caution should be exercised when extrapolating results obtained in one racial or ethnic group, such as Northern Europeans, to other racial or ethnic groups. Most importantly, we must deploy genomics into practice in an effective, efficient, equitable, patient-centred and safe fashion.

Precision medicine will fall far short of its promise if the costs are so high that they make it unavailable to everyone. Moving forward, our challenge will be to embrace precision medicine with intellectual discipline such that we don’t waste money, resources or time - for clinicians or patients. It is also important to ensure that the costs of precision medicine do not displace other social priorities that have a significant impact on health and wellbeing.

Although much knowledge will arise in basic science laboratories and universities, learning health systems will likely play a key role in developing practices that are applicable to real world settings. In the future, we will be able to deliver more accessible, personalized care by integrating evidence-based genomics and other omics into well-designed patient-centred care pathways.

Both authors are MDs.