Public health, prevention to play role in precision medicine: Interventions aimed at individual risks
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* Natalie McGill

No crystal ball exists to show exactly how people will react to medications or if they are at higher risk for certain cancers, but thanks to advances in precision medicine, researchers may get close.

Precision medicine — the practice of developing targeted interventions or medical treatments based on a person’s environment, genetics and lifestyle — is under the national microscope following the January launch of President Barack Obama’s Precision Medicine Initiative.

Goals of the initiative include improved targeted cancer treatments and recruiting a cohort of more than 1 million Americans who will contribute data such as their genetic makeup for future clinical trials and research.

But while precision medicine has the means to revolutionize how health professionals treat disease, researchers are also looking at the benefits it can have on prevention and public health.

“In the public health sphere, the near-term gains are pretty clear,” said James Evans, MD, PhD, director of the Bryson Program for Human Genetics at the University of North Carolina-Chapel Hill. “They will come from our ability to identify those individuals in the population who unknowingly harbor substantial risk of a severe but preventable disease. About one in 250 people, for example are walking around out there with a mutation in their genome that leads to a high risk of colorectal cancer. This is highly actionable, and colon cancer can be readily prevented when we know about that risk. We now have genomic technology to identify those people who have such mutations.”

![Figure1](http://www.thenationshealth.org/http://www.thenationshealth.org/content/nathealth/45/7/1.3/F1.medium.gif)

[Figure1](http://www.thenationshealth.org/content/45/7/1.3/F1)

Perla Del Pino-White, DO, right, examines Felue Chang at a health clinic in Hollywood, Florida, in April 2014. In the future, doctors may rely on precision medicine — in which interventions are tailored to an individual’s environment, genetics and lifestyle — to provide prevention and health promotion advice.

Photo by Joe Raedle, courtesy Getty Images

Discoveries made through precision medicine could allow a greater focus on disease prevention, according to Muin Khoury, MD, PhD, director of the Office of Public Health Genomics at the Centers for Disease Control and Prevention.

Take the example of a hypothetical 50-year-old woman with Type 2 diabetes, which Khoury mentioned in a June 2 CDC blog post. The woman enrolls in the cohort and within five years, changes her diet and uses more precise medication to achieve better health based on an analysis of both her DNA and glucose levels monitored by a computer chip implant. Precision medicine based on lifestyle and genetics could track people who have pre-diabetes and connect them with proven interventions, such as CDC’s National Diabetes Prevention Program, Khoury said.

“We’ll have the tools to be able to measure risk factors both at the individual and population levels more accurately and use them for public health and prevention programs,” Khoury told *The Nation’s Health.*

At the Duke Center for Applied Genomics and Precision Medicine, researchers working on the center’s MeTree program give physicians tools to determine a patient’s risk for 30 diseases based on an analysis of family health history.

MeTree falls under one of the center’s five focus areas: risk assessment. Center researchers are looking at people who are healthy and investigating how to keep them healthy, said Lori Orlando, MD, MHS, associate director in the Duke Center for Applied Genomics and Precision Medicine and director of the center’s program in precision medicine.

“The patient gets information saying ‘Based on the information you entered, you are at increased risk for these things, and you should talk about that with your doctor,’” Orlando told *The Nation’s Health.* “The doctor gets something that says, ‘This patient’s breast cancer risk score is ‘x’ and they meet criteria for breast MRI. This is why. Here are the guidelines.’ That allows them to have a discussion at the visit.”

![Figure2](http://www.thenationshealth.org/http://www.thenationshealth.org/content/nathealth/45/7/1.3/F2.medium.gif)

[Figure2](http://www.thenationshealth.org/content/45/7/1.3/F2)

Precision medicine holds promise for researchers to determine disease risks based on factors such as family health history.

Photo by DragonImages, courtesy iStockphoto

Outside of MeTree, center researchers also developed a virtual world for patients with diabetes that allows them to create avatars — images representing people online — and enter an environment where they can socialize, obtain educational materials about managing chronic conditions, and collaborate with other patients about what they do and do not do to manage their care.

“When we identify people who are at increased risk and weren’t known to be…they are able to get more appropriate risk management services to prevent disease,” Orlando said.

Applying precision medicine to public health is critical, Orlando said. Without precision medicine, health professionals apply an intervention for a disease based on the results of clinical studies, yet some people in those studies fare worse while others get much better.

“Targeting the right thing to the right patient will reduce costs, decrease side effects and improve the efficacy of the interventions when they are applied to the right person,” Orlando said. “From a prevention standpoint, that is the most important thing because people aren’t going to keep doing something that won’t work for them.”

Realizing the importance of health disparities in population health, both Evans and Khoury stressed that the 1 million people volunteering for the Precision Medicine Initiative research cohort should be inclusive and diverse. The cohort, which is recommended to be created within five years, will include genomic, clinical and other health information on participants.

“Data from large numbers of people are required to identify characteristics, including genetic markers predictive of treatment response,” they wrote in a June 2 article in the *Journal of the American Medical Association.* “Moreover, from a public health perspective, collecting information from large numbers of people is far more informative when these people reflect the diversity of the underlying population.”

Having a diverse population is a challenge of making precision medicine work for public health, Evans said. Researchers must use a variety of ways to reach people, as not everyone has Internet access, and have long-term follow up with the ability to re-contact people, he said.

“Just a snapshot doesn’t help as much,” Evans told *The Nation’s Health.* “When you think about ties to genomic changes, someone may be perfectly healthy and the next year they are sick. That’s the challenge with a mobile society. Then you have to balance privacy and confidentiality issues. People are protective of their information. This cohort will have to navigate those complexities and achieve long-term follow-up.”

The other challenge in making precision medicine work for prevention and public health is making the public understand that research takes time to develop and that precision medicine will not suddenly revolutionize their doctor’s appointments even in the next decade.

“On the other hand, it doesn’t meant we shouldn’t use the technology to learn, because we will learn very important things,” Evans said. “This is how health improves. We live in a society that embraces things excitedly and when they don’t pay off, they move onto the next thing. That’s how we can’t afford to act when it comes to science. Precision medicine and science are long-term endeavors.”

For more information on the Precision Medicine Initiative and its implications for public health, visit [www.whitehouse.gov/precision-medicine](http://www.whitehouse.gov/precision-medicine) and [www.cdc.gov/genomics](http://www.cdc.gov/genomics).

*   Copyright The Nation’s Health, American Public Health Association