If you get sick, your doctor might suggest that you get the treatment that works for most or all adults with the same illness. But for some illnesses that one-size-fits-all approach isn’t the best option anymore.
A boom in genetic research has allowed doctors to treat some conditions with precision medicine -- personalized treatment based on your unique genetic makeup. You might also hear it referred to as “personalized medicine” or “genomic medicine.” This cutting-edge practice takes your environment and lifestyle into account, too.
How It Works: Genes
DNA units called genes make up your cells and give you your basic human traits, as well as your unique physical features. Precision medicine uses information from your genes to find out what conditions you’re likely to get. Mostly, though, it’s focused on treatment.
“We look at a patient’s genetic makeup -- or often, in the case of cancer, the genetic makeup of their tumor," says Stefan C. Grant, MD, an oncologist (cancer doctor) at Wake Forest Baptist Medical Center in North Carolina. Depending on the research available, he says, that information can sometimes show if there’s a particular medical treatment that will work.
For instance, if you’re diagnosed with breast cancer, the doctor might suggest you get genetic testing to help her come up with a treatment plan. To do that, she’ll collect a sample of your blood or spit and send it to a lab for tests.
If the results show that you have genetic changes (she’ll call them mutations) like BRCA1 or BRCA2, the doctor knows your cancer is more likely to respond to treatments that might not be the standard she’d suggest to most patients.
“Genetics aren’t destiny. But in some cases, they can provide additional information that may help your medical team determine the approach that’s right for you,” says Elizabeth A. McGlynn, PhD, vice president of Kaiser Permanente's Center for Effectiveness and Safety Research, which oversees the organization's personalized medicine efforts.
How It Works: Lifestyle and Environment
Precision medicine isn’t just about genetics. More and more, experts also need information about your individual and family healthy history, lifestyle factors (like diet and exercise habits), and environment -- things you were exposed to where you grew up and where you live now (like the air, water, and quality of the area).
Scientists want to figure out what role these non-genetic factors play in how diseases form and progress. Think about diabetes and certain kidney conditions. You can have genetic changes linked to that disease but never get it. That suggests that where you live or what you eat could affect whether the gene was “turned on” and led to an active disease.
“We’re at an early stage of learning how best to put all of this information together to help patients make decisions with their doctors about how to best achieve health goals,” McGlynn says.
To help with the effort, the NIH has launched the Precision Medicine Initiative to encourage research, technology, and public policy to support precision medicine. It’s a huge project that aims to gather health information from volunteers across the U.S. Currently the program is recruiting volunteers. For details, check the project’s website, www.joinallofus.org.
Those who join up may be asked to get a baseline medical exam, give blood, and agree to share:
- Electronic health records
- Health survey information
- Mobile health data on lifestyle and environment
Experts think the combination of genetic, lifestyle, and health history information will help doctors and scientists come up with better treatments and prevention strategies.
Precision Medicine in Action
In addition to the NIH project, medical centers and universities around the country are working to come up with new information that will help doctors pair the right patients with the right medications.
Some people can already see benefits of precision medicine. “The most promising area to date is cancer,” McGlynn says. Right now, your doctors can use genetic testing to figure out if you’re more likely to get certain forms of cancer. If your genes show that your odds are higher than average, your doctor will suggest ways to help lower them.
Cancer tumors contain information about you, too. If you get one of a handful of cancers, your doctor may take a small piece of the tumor (this procedure is called a biopsy) to check it for genetic information. Depending on the results, she can tailor treatment based on your genes.
For example, researchers now know that tumors from different parts of the body can be alike. That’s changed the way they’re treated. They also know that people with leukemia (a form of blood cancer) who have a certain genetic makeup respond well to a drug called imatinib (Gleevec).
Doctors are using precision medicine to treat lung cancer, melanoma (skin cancer), colon cancer, and pancreatic cancer. It can also help with some rare childhood illnesses, cystic fibrosis, and HIV. It may soon show up in treatment plans for heart disease, rheumatoid arthritis, Alzheimer’s disease, multiple sclerosis, and many other conditions.
Is It Right for You?
McGlynn says the best way to find out is to ask your doctor this question: “Would getting a genetic test help guide my choice of treatment?” If the answer is “no,” it isn’t always a bad thing. Standard treatments work well for many diseases. “With cancer, chemotherapy is still incredibly important,” Grant says. Precision medicine won’t take it out of the playbook.
In fact, these new treatments are mostly used for patients with advanced cancer. Drugs that treat early-stage cancers have been heavily tested and are known to be safe. “Genomically targeted drugs often have less research in the early stage setting behind them,” says Milan Radovich, PhD, medical co-director of the Indiana University/IU Health Precision Genomics Program in Indianapolis. “That will continue to evolve as more clinical trials are conducted.”
Precision medicine may also be more useful for conditions like rare childhood illnesses where few or no other effective treatments exist. Some precision drugs work better than standard treatments for some people, but doctors urge caution because everyone responds differently. And often, when a disease is advanced, “the goal is to control, rather than cure, the cancer,” Grant says.
Insurance often pays for precision medicine, especially for cancer treatment. Coverage for genetic testing varies, especially if you’re doing it to prevent, not cure, a disease. Many hospitals and medical centers have staff who can help you determine your insurance coverage.
What Does the Future Hold?
Today, precision medicine is in its early stages. “We still don’t understand the genetic component of most diseases -- and even when we do, we don’t always have a solution that’s ready for prime time,” McGlynn says. “But I can’t think of a single area of medicine where researchers aren’t exploring the role genes play in treatment and prevention.”
And with an explosion of research underway, it may not be long before many more -- if not most -- people can benefit from these treatments. One promising area of research, Radovich says, is “basket trials.” That’s where cancer drugs are prescribed based on the genetic mutation of a tumor, rather than the type of tumor (such as breast, lung, or prostate).
“It’s about what makes a tumor tick, rather than where it came from,” Radovich says. “These trials provide patients access to a lot of drugs that may not normally be prescribed, which may offer new hope for hard-to-treat cancers.”
Looking ahead, Eric Dishman, director of the All of Us Project, sees a wealth of information at researchers’ fingertips that will make precision medicine that much more precise.
“Ten years from now, with the benefit of years of data contributed by more than 1 million people, we are going to know even more about what actions each person can take to keep themselves healthier,” he says. “My vision is, ultimately, that everyone has that information and nobody will have to suffer through trial-and-error care."